Date: Sun, 1 Aug 2004 07:58:54 -0500 From: "James A. Coulter" <james.coulter@cox.net> To: <freebsd-questions@freebsd.org> Cc: Barbish3@adelphia.net Subject: RE: Firewall Rule Set not allowing access to DNS servers? Message-ID: <001001c477c7$4cdac720$6e01a8c0@sabrina> In-Reply-To: <MIEPLLIBMLEEABPDBIEGEEDDGIAA.Barbish3@adelphia.net>
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I changed the DNS rules as you suggested, and the firewall works perfectly - thanks very much. This has been a great learning experience for me - thanks to all who responded. Jim C > -----Original Message----- > From: JJB [mailto:Barbish3@adelphia.net] > Sent: Saturday, July 31, 2004 1:08 PM > To: James A. Coulter; freebsd-questions@freebsd.org > Subject: RE: Firewall Rule Set not allowing access to DNS servers? > > > Look back at the ipfw sample rule set and you will see that > there are both udp and tcp protocol access to DSN. Also not > that udp does not use setup keyword. > > # Allow out access to my ISP's Domain name server. > # x.x.x.x must be the IP address of your ISP's DNS > # Dup these lines if your ISP has more than one DNS server > # Get the IP addresses from /etc/resolv.conf file > $cmd 00110 allow tcp from any to x.x.x.x 53 out via $pif > setup keep-state $cmd 00111 allow udp from any to x.x.x.x 53 > out via $pif keep-state > > You DNS rules are > # Allow out access to my ISP's Domain name server. > # x.x.x.x must be the IP address of your ISP's DNS > # Dup these lines if your ISP has more than one DNS server > # Get the IP addresses from /etc/resolv.conf file > $cmd 020 $skip UDP from any to 68.105.161.20 53 out via $pif > setup keep-state $cmd 021 $skip UDP from any to 68.1.18.25 53 > out via $pif setup keep-state $cmd 022 $skip UDP from any to > 68.10.16.30 53 out via $pif setup keep-state > > As you can see you have no tcp protocol statements. > Your udp rules use setup keyword which is only for tcp rules > so your udp packets never match this rule and default to > getting blocked which is why you get log error messages and > you can not access public internet. > > Also if you look closely at the first 4 ipfw log messages you > will see first message is about ip address 193.0.14.129 which is the > primary dns server pointed to by url search pn.at.cox.net in > /etc/resolv.conf > > Change your DNS rules to look like this > > # Allow out access to my ISP's Domain name server. > # x.x.x.x must be the IP address of your ISP's DNS > # Dup these lines if your ISP has more than one DNS server > # Get the IP addresses from /etc/resolv.conf file > $cmd 020 $skip udp from any to 193.0.14.129 53 out via $pif > keep-state $cmd 021 $skip udp from any to 68.1.18.25 53 out > via $pif keep-state $cmd 022 $skip udp from any to > 68.10.16.30 53 out via $pif keep-state $cmd 023 $skip udp > from any to 68.105.161.20 53 out via $pif keep-state $cmd 024 > $skip tcp from any to 193.0.14.129 53 out via $pif setup > keep-state $cmd 025 $skip tcp from any to 68.1.18.25 53 out > via $pif setup keep-state $cmd 026 $skip tcp from any to > 68.10.16.30 53 out via $pif setup keep-state $cmd 027 $skip > tcp from any to 68.105.161.20 53 out via $pif setup keep-state > > -----Original Message----- > From: owner-freebsd-questions@freebsd.org > [mailto:owner-freebsd-questions@freebsd.org]On Behalf Of > James A. Coulter > Sent: Saturday, July 31, 2004 1:09 PM > To: Barbish3@adelphia.net; freebsd-questions@freebsd.org > Subject: RE: Firewall Rule Set not allowing access to DNS servers? > > My LAN is configured with static IP addresses, 192.168.1.x. > > I have no problems communicating within the LAN. > > I have full connectivity with the internet from every machine > on my LAN when the firewall is open. > > When I use the rule set in question, I can ping and send mail > but I cannot access the DNS servers listed in resolv.conf. > > These are the same DNS servers placed in resolv.conf when the > firewall is open. > > I'm sorry, but I never said dc1 was my inside nic. > > Again, I appreciate any help with this. The files you > requested follow. > > Here's my ifconfig - a: > > sara# ifconfig -a > dc0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 > inet 192.168.1.1 netmask 0xffffff00 broadcast 192.168.1.255 > inet6 fe80::204:5aff:fe76:55f0%dc0 prefixlen 64 scopeid 0x1 > ether 00:04:5a:76:55:f0 > media: Ethernet autoselect (100baseTX <full-duplex>) > status: active > dc1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 > inet6 fe80::2a0:ccff:fe33:e1f6%dc1 prefixlen 64 scopeid 0x2 > inet 68.105.58.150 netmask 0xfffffe00 broadcast 68.105.59.255 > ether 00:a0:cc:33:e1:f6 > media: Ethernet autoselect (100baseTX <full-duplex>) > status: active > lp0: flags=8810<POINTOPOINT,SIMPLEX,MULTICAST> mtu 1500 > lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384 > inet6 ::1 prefixlen 128 > inet6 fe80::1%lo0 prefixlen 64 scopeid 0x4 > inet 127.0.0.1 netmask 0xff000000 > ppp0: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 > sl0: flags=c010<POINTOPOINT,LINK2,MULTICAST> mtu 552 > faith0: flags=8002<BROADCAST,MULTICAST> mtu 1500 > > Here's resolv.conf: > > sara# more /etc/resolv.conf > search pn.at.cox.net > nameserver 68.105.161.20 > nameserver 68.1.18.25 > nameserver 68.10.16.30 > > Here's the entire rule set I'm trying to use. > > I did follow the comments. > > Please note the variable pif is set to dc1, my outside nic. > > ################ Start of IPFW rules file > ############################### # Flush out the list before > we begin. ipfw -q -f flush # Set rules command prefix > cmd="ipfw -q add" skip="skipto 800" > pif="dc1" # public interface name of Nic card > # facing the public internet > > > > ################################################################# > # No restrictions on Inside Lan Interface for private network > # Change xl0 to your Lan Nic card interface name > ################################################################# > $cmd 005 allow all from any to any via dc0 > > ################################################################# > # No restrictions on Loopback Interface > ################################################################# > $cmd 010 allow all from any to any via lo0 > > ################################################################# > # check if packet is inbound and nat address if it is > ################################################################# > $cmd 014 divert natd ip from any to any in via $pif > > ################################################################# > # Allow the packet through if it has previous been added to > the # the "dynamic" rules table by a allow keep-state > statement. > ################################################################# > $cmd 015 check-state > > ################################################################# > # Interface facing Public internet (Outbound Section) > # Interrogate session start requests originating from behind > the # firewall on the private network or from this gateway > server # destine for the public internet. > ################################################################# > > # Allow out access to my ISP's Domain name server. > # x.x.x.x must be the IP address of your ISP's DNS > # Dup these lines if your ISP has more than one DNS server > # Get the IP addresses from /etc/resolv.conf file > $cmd 020 $skip UDP from any to 68.105.161.20 53 out via $pif > setup keep-state $cmd 021 $skip UDP from any to 68.1.18.25 53 > out via $pif setup keep-state $cmd 022 $skip UDP from any to > 68.10.16.30 53 out via $pif setup keep-state > > # Allow out access to my ISP's DHCP server for cable/DSL > configurations. $cmd 030 $skip udp from any to 172.19.17.22 > 67 out via $pif keep-state > > # Allow out non-secure standard www function > $cmd 040 $skip tcp from any to any 80 out via $pif setup keep-state > > # Allow out secure www function https over TLS SSL > $cmd 050 $skip tcp from any to any 443 out via $pif setup keep-state > > # Allow out send & get email function > $cmd 060 $skip tcp from any to any 25 out via $pif setup > keep-state $cmd 061 $skip tcp from any to any 110 out via > $pif setup keep-state > > # Allow out FBSD (make install & CVSUP) functions > # Basically give user root "GOD" privileges. > $cmd 070 $skip tcp from me to any out via $pif setup > keep-state uid root > > # Allow out ping > $cmd 080 $skip icmp from any to any out via $pif keep-state > > # Allow out Time > $cmd 090 $skip tcp from any to any 37 out via $pif setup keep-state > > # Allow out nntp news (IE: news groups) > $cmd 100 $skip tcp from any to any 119 out via $pif setup keep-state > > # Allow out secure FTP, Telnet, and SCP > # This function is using SSH (secure shell) > $cmd 110 $skip tcp from any to any 22 out via $pif setup keep-state > > # Allow out whois > $cmd 120 $skip tcp from any to any 43 out via $pif setup keep-state > > # Allow ntp time server > $cmd 130 $skip udp from any to any 123 out via $pif keep-state > > ################################################################# > # Interface facing Public internet (Inbound Section) > # Interrogate packets originating from the public internet > # destine for this gateway server or the private network. > ################################################################# > > # Deny all inbound traffic from non-routable reserved address > spaces $cmd 300 deny all from 192.168.0.0/16 to any in via > $pif #RFC 1918 private IP > $cmd 301 deny all from 172.16.0.0/12 to any in via $pif #RFC 1918 > private > IP > $cmd 302 deny all from 10.0.0.0/8 to any in via $pif #RFC 1918 > private > IP > $cmd 303 deny all from 127.0.0.0/8 to any in via $pif #loopback > $cmd 304 deny all from 0.0.0.0/8 to any in via $pif #loopback > $cmd 305 deny all from 169.254.0.0/16 to any in via $pif > #DHCP auto-config > $cmd 306 deny all from 192.0.2.0/24 to any in via $pif #reserved > for > doc's > $cmd 307 deny all from 204.152.64.0/23 to any in via $pif > #Sun cluster > $cmd 308 deny all from 224.0.0.0/3 to any in via $pif #Class D > & E > multicast > > # Deny ident > $cmd 315 deny tcp from any to any 113 in via $pif > > # Deny all Netbios service. 137=name, 138=datagram, > 139=session # Netbios is MS/Windows sharing services. # Block > MS/Windows hosts2 name server requests 81 $cmd 320 deny tcp > from any to any 137 in via $pif $cmd 321 deny tcp from any to > any 138 in via $pif $cmd 322 deny tcp from any to any 139 in > via $pif $cmd 323 deny tcp from any to any 81 in via $pif > > # Deny any late arriving packets > $cmd 330 deny all from any to any frag in via $pif > > # Deny ACK packets that did not match the dynamic rule table > $cmd 332 deny tcp from any to any established in via $pif > > # Allow traffic in from ISP's DHCP server. This rule must > contain # the IP address of your ISP's DHCP server as it's > the only # authorized source to send this packet type. # Only > necessary for cable or DSL configurations. # This rule is not > needed for 'user ppp' type connection to # the public > internet. This is the same IP address you captured # and used > in the outbound section. $cmd 360 allow udp from 172.19.17.22 > to any 68 in via $pif keep-state > > # Allow in standard www function because I have apache server > $cmd 370 allow tcp from any to me 80 in via $pif setup limit > src-addr 2 $cmd 370 allow tcp from any to me 8888 in via $pif > setup limit src-addr 2 > > # Allow in secure FTP, Telnet, and SCP from public Internet > $cmd 380 allow tcp from any to me 22 in via $pif setup limit > src-addr 2 > > # Allow in non-secure Telnet session from public Internet > # labeled non-secure because ID & PW are passed over public > # internet as clear text. > # Delete this sample group if you do not have telnet server > enabled. # $cmd 390 allow tcp from any to me 23 in via $pif > setup limit src-addr 2 > > # Reject & Log all unauthorized incoming connections from the > public internet $cmd 500 deny log all from any to any in via $pif > > # Reject & Log all unauthorized out going connections to the > public internet > > $cmd 550 deny log all from any to any out via $pif > > # This is skipto location for outbound stateful rules > $cmd 800 divert natd ip from any to any out via $pif > $cmd 801 allow ip from any to any > > # Everything else is denied by default > # deny and log all packets that fell through to see what they > are $cmd 999 deny log all from any to any > > > ################ End of IPFW rules file > ############################### > > Here's all of today's security ouput: > > Jul 31 07:50:36 sara /kernel: ipfw: 550 Deny UDP > 68.105.58.150:1649 193.0.14.129:53 out via dc1 Jul 31 > 07:50:37 sara /kernel: ipfw: 550 Deny UDP 68.105.58.150:2671 > 68.105.161.20:53 out via dc1 Jul 31 07:50:37 sara /kernel: > ipfw: 550 Deny UDP 68.105.58.150:1042 68.1.18.25:53 out via > dc1 Jul 31 07:50:37 sara /kernel: ipfw: 550 Deny UDP > 68.105.58.150:4365 68.10.16.30:53 out via dc1 Jul 31 07:50:37 > sara /kernel: ipfw: 550 Deny UDP 68.105.58.150:2365 > 68.105.161.20:53 out via dc1 Jul 31 07:50:37 sara /kernel: > ipfw: 550 Deny UDP 68.105.58.150:4325 68.1.18.25:53 out via > dc1 Jul 31 07:50:37 sara /kernel: ipfw: 550 Deny UDP > 68.105.58.150:3378 68.10.16.30:53 out via dc1 Jul 31 07:50:37 > sara /kernel: ipfw: 550 Deny UDP 68.105.58.150:2952 > 68.105.161.20:53 out via dc1 Jul 31 07:50:37 sara /kernel: > ipfw: 550 Deny UDP 68.105.58.150:1359 68.1.18.25:53 out via > dc1 Jul 31 07:50:37 sara /kernel: ipfw: 550 Deny UDP > 68.105.58.150:4738 68.10.16.30:53 out via dc1 Jul 31 07:50:37 > sara /kernel: ipfw: limit 10 reached on entry 550 Jul 31 > 07:51:42 sara /kernel: ipfw: 500 Deny TCP 81.56.103.50:3860 > 68.105.58.150:21 in via dc1 Jul 31 07:51:51 sara last message > repeated 2 times Jul 31 07:53:15 sara /kernel: ipfw: 500 Deny > TCP 81.56.103.50:3875 68.105.58.150:21 in via dc1 Jul 31 > 07:53:24 sara last message repeated 2 times Jul 31 07:53:32 > sara /kernel: ipfw: 500 Deny TCP 81.56.103.50:3878 > 68.105.58.150:21 in via dc1 Jul 31 07:53:41 sara last message > repeated 2 times Jul 31 07:53:44 sara /kernel: ipfw: 500 Deny > TCP 81.56.103.50:3881 68.105.58.150:21 in via dc1 Jul 31 > 07:53:44 sara /kernel: ipfw: limit 10 reached on entry 500 > Jul 31 08:13:35 sara /kernel: ipfw: 65000 Deny UDP > 68.1.18.25:53 192.168.1.102:3232 in via dc1 Jul 31 08:13:35 > sara /kernel: ipfw: 65000 Deny UDP 68.105.161.20:53 > 192.168.1.102:3232 in via dc1 Jul 31 08:14:33 sara /kernel: > ipfw: 65000 Deny UDP 10.2.184.1:67 255.255.255.255:68 in via > dc1 Jul 31 08:15:28 sara last message repeated 2 times Jul 31 > 08:15:47 sara last message repeated 5 times Jul 31 08:15:47 > sara /kernel: ipfw: limit 10 reached on entry 65000 Jul 31 > 08:31:20 sara /kernel: ipfw: 550 Deny UDP 68.105.58.150:3534 > 198.41.0.4:53 out via dc1 Jul 31 08:31:21 sara /kernel: ipfw: > 550 Deny UDP 68.105.58.150:3178 68.105.161.20:53 out via dc1 > Jul 31 08:31:21 sara /kernel: ipfw: 550 Deny UDP > 68.105.58.150:4476 68.1.18.25:53 out via dc1 Jul 31 08:31:21 > sara /kernel: ipfw: 550 Deny UDP 68.105.58.150:4747 > 68.10.16.30:53 out via dc1 Jul 31 08:31:21 sara /kernel: > ipfw: 550 Deny UDP 68.105.58.150:4952 68.105.161.20:53 out > via dc1 Jul 31 08:31:21 sara /kernel: ipfw: 550 Deny UDP > 68.105.58.150:2260 68.1.18.25:53 out via dc1 Jul 31 08:31:21 > sara /kernel: ipfw: 550 Deny UDP 68.105.58.150:4087 > 68.10.16.30:53 out via dc1 Jul 31 08:31:21 sara /kernel: > ipfw: 550 Deny UDP 68.105.58.150:4914 68.105.161.20:53 out > via dc1 Jul 31 08:31:21 sara /kernel: ipfw: 550 Deny UDP > 68.105.58.150:1849 68.1.18.25:53 out via dc1 Jul 31 08:31:21 > sara /kernel: ipfw: 550 Deny UDP 68.105.58.150:2220 > 68.10.16.30:53 out via dc1 Jul 31 08:31:21 sara /kernel: > ipfw: limit 10 reached on entry 550 > > Here's rc.conf again: > > # -- sysinstall generated deltas -- > # Sun Jul 4 10:40:48 2004 > # Created: Sun Jul 4 10:40:48 2004 > # Enable network daemons for user convenience. > # Please make all changes to this file, not to > /etc/defaults/rc.conf. # This file now contains just the > overrides from /etc/defaults/rc.conf. > hostname="sara.mshome.net" ifconfig_dc1="DHCP" > ifconfig_dc0="inet 192.168.1.1 netmask 255.255.255.0" > firewall_enable="YES" firewall_script="/etc/ipfw.rules" > firewall_logging="YES" kern_securelevel_enable="NO" > linux_enable="YES" moused_enable="YES" named_enable="YES" > nfs_client_enable="YES" nfs_reserved_port_only="YES" > nfs_server_enable="YES" sendmail_enable="YES" > sshd_enable="YES" usbd_enable="YES" ntpd_enable="YES" > inetd_enable="YES" gateway_enable="YES" natd_enable="YES" > natd_interface="dc1" natd_flags="-dynamic" > > Here's dmesg.boot: > > Copyright (c) 1992-2004 The FreeBSD Project. > Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, > 1993, 1994 > The Regents of the University of California. All > rights reserved. FreeBSD 4.10-RELEASE #8: Fri Jul 30 07:19:43 CDT 2004 > jcoulter@sara.mshome.net:/usr/obj/usr/src/sys/SARA > Timecounter "i8254" frequency 1193182 Hz > CPU: Intel Celeron (634.78-MHz 686-class CPU) > Origin = "GenuineIntel" Id = 0x686 Stepping = 6 > > Features=0x383f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,M > CA,CMOV, > PAT,PSE36,MMX,FXSR,SSE> > real memory = 134201344 (131056K bytes) > avail memory = 127057920 (124080K bytes) > Preloaded elf kernel "kernel" at 0xc0381000. > Pentium Pro MTRR support enabled > md0: Malloc disk > Using $PIR table, 8 entries at 0xc00f0e80 > npx0: <math processor> on motherboard > npx0: INT 16 interface > pcib0: <Intel 82443BX (440 BX) host to PCI bridge> on motherboard > pci0: <PCI bus> on pcib0 > agp0: <Intel 82443BX (440 BX) host to PCI bridge> mem > 0xe4000000-0xe7ffffff at device 0.0 on pci0 > pcib1: <Intel 82443BX (440 BX) PCI-PCI (AGP) bridge> at > device 1.0 on pci0 > pci1: <PCI bus> on pcib1 > pci1: <ATI Mach64-GB graphics accelerator> at 0.0 irq 11 > isab0: <Intel 82371AB PCI to ISA bridge> at device 4.0 on pci0 > isa0: <ISA bus> on isab0 > atapci0: <Intel PIIX4 ATA33 controller> port 0xb800-0xb80f at > device 4.1 on pci0 > ata0: at 0x1f0 irq 14 on atapci0 > ata1: at 0x170 irq 15 on atapci0 > uhci0: <Intel 82371AB/EB (PIIX4) USB controller> port > 0xb400-0xb41f irq 9 at device 4.2 on pci0 > usb0: <Intel 82371AB/EB (PIIX4) USB controller> on uhci0 > usb0: USB revision 1.0 > uhub0: Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1 > uhub0: 2 ports with 2 removable, self powered > chip0: <Intel 82371AB Power management controller> port > 0xe800-0xe80f at device 4.3 on pci0 > dc0: <ADMtek AN985 10/100BaseTX> port 0xb000-0xb0ff mem > 0xe1000000-0xe10003ff irq 12 at device 10.0 on pci0 > dc0: Ethernet address: 00:04:5a:76:55:f0 > miibus0: <MII bus> on dc0 > ukphy0: <Generic IEEE 802.3u media interface> on miibus0 > ukphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto > dc1: <LC82C115 PNIC II 10/100BaseTX> port 0xa800-0xa8ff mem > 0xe0800000-0xe08000ff irq 10 at device 11.0 on pci0 > dc1: Ethernet address: 00:a0:cc:33:e1:f6 > miibus1: <MII bus> on dc1 > dcphy0: <Intel 21143 NWAY media interface> on miibus1 > dcphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto > isa0: too many dependant configs (8) > isa0: unexpected small tag 14 > orm0: <Option ROM> at iomem 0xc0000-0xc7fff on isa0 > pmtimer0 on isa0 > fdc0: <NEC 72065B or clone> at port 0x3f0-0x3f5,0x3f7 irq 6 > drq 2 on isa0 > fdc0: FIFO enabled, 8 bytes threshold > fd0: <1440-KB 3.5" drive> on fdc0 drive 0 > atkbdc0: <Keyboard controller (i8042)> at port 0x60,0x64 on isa0 > atkbd0: <AT Keyboard> flags 0x1 irq 1 on atkbdc0 > kbd0 at atkbd0 > vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem > 0xa0000-0xbffff on isa0 > sc0: <System console> at flags 0x100 on isa0 > sc0: VGA <16 virtual consoles, flags=0x300> > sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0 > sio0: type 16550A > sio1 at port 0x2f8-0x2ff irq 3 on isa0 > sio1: type 16550A > ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0 > ppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode > ppc0: FIFO with 16/16/9 bytes threshold > plip0: <PLIP network interface> on ppbus0 > lpt0: <Printer> on ppbus0 > lpt0: Interrupt-driven port > ppi0: <Parallel I/O> on ppbus0 > IP packet filtering initialized, divert enabled, rule-based > forwarding enabled, default to deny, logging limited to 10 > packets/entry by default > ad0: DMA limited to UDMA33, non-ATA66 cable or device > ad0: 19623MB <IBM-DTLA-305020> [39870/16/63] at ata0-master UDMA33 > acd0: CDROM <SONY CD-ROM CDU4821> at ata0-slave PIO4 > Mounting root from ufs:/dev/ad0s1a > > Thanks, > > Jim C. > > > > > -----Original Message----- > > From: JJB [mailto:Barbish3@adelphia.net] > > Sent: Saturday, July 31, 2004 10:28 AM > > To: James A. Coulter; freebsd-questions@freebsd.org > > Subject: RE: Firewall Rule Set not allowing access to DNS servers? > > > > > > You better re-read what you posted in early post. You > posted that dc1 > > is your outside NIC, which is connected to your cable modem > which is > > connected to your ISP. Your outside NIC needs DHCP to get > ip and dns > > info from your ISP. NOW YOU SAY dc1 IS INSIDE INTERFACE > NAME. Make up > > your mind which is correct. > > > > Verify you have correct interface name coded in ipfw rules for NIC > > connected to cable modem and that the same NIC interface > name is the > > one in rc.conf with DHCP option. When DHCP gets DNS info from ISP > > /etc/resolv.conf will auto updated with correct info. Read > comments in > > sample firewall source and follow what comments say. You > are making > > this harder than it really is. > > > > Also there is no setup option on UDP packets just keepstate > > > > Post full contents of your current dmesg.boot, rc.conf, ipfw rule > > set, and ipfw log files so people can see just want you have > > configured. And answer question of how you are assigning > ip address > > to LAN PCs? Also post output of ifconfig -a command after boot > > completes. > > > > > > -----Original Message----- > > From: owner-freebsd-questions@freebsd.org > > [mailto:owner-freebsd-questions@freebsd.org]On Behalf Of James A. > > Coulter > > Sent: Saturday, July 31, 2004 9:55 AM > > To: freebsd-questions@freebsd.org > > Cc: Barbish3@adelphia.net > > Subject: RE: Firewall Rule Set not allowing access to DNS servers? > > > > Thanks for the response. . . > > > > I changed rule 00005 from x10 to dc0 - thanks > > > > Not sure why I would want my inside nic requesting DHCP > service from > > my ISP. It has been working fine in the configuration I have it so > > I've left it the way it is. > > > > I checked the security log, and found this: > > > > Jul 30 08:58:37 sara /kernel: ipfw: 450 Deny UDP 68.105.58.150:2609 > > 68.105.161.20:53 out via dc1 Jul 30 08:58:37 sara /kernel: > ipfw: 450 > > Deny UDP 68.105.58.150:4067 68.1.18.25:53 out via dc1 Jul > 30 08:58:37 > > sara /kernel: ipfw: 450 Deny UDP 68.105.58.150:3773 > 68.10.16.30:53 out > > via dc1 > > > > These are the three name servers specified in the rule set > > > > I checked the rule set and found this: > > > > # Allow out access to my ISP's Domain name server. > > # x.x.x.x must be the IP address of your ISP's DNS > > # Dup these lines if your ISP has more than one DNS server > > # Get the IP addresses from /etc/resolv.conf file > > $cmd 020 $skip tcp from any to 68.105.161.20 53 out via $pif setup > > keep-state $cmd 021 $skip tcp from any to 68.1.18.25 53 out > via $pif > > setup keep-state $cmd 022 $skip tcp from any to 68.10.16.30 > 53 out via > > $pif setup keep-state > > > > Because security said the firewall was denying UDP packets, > I changed > > the rules to this: > > > > $cmd 020 $skip udp from any to 68.105.161.20 53 out via $pif setup > > keep-state $cmd 021 $skip udp from any to 68.1.18.25 53 out > via $pif > > setup keep-state $cmd 022 $skip udp from any to 68.10.16.30 > 53 out via > > $pif setup keep-state > > > > But that hasn't helped. I'm still getting: > > > > Jul 31 08:31:21 sara /kernel: ipfw: 550 Deny UDP 68.105.58.150:3178 > > 68.105.161.20:53 out via dc1 Jul 31 08:31:21 sara /kernel: > ipfw: 550 > > Deny UDP 68.105.58.150:4476 68.1.18.25:53 out via dc1 Jul > 31 08:31:21 > > sara /kernel: ipfw: 550 Deny UDP 68.105.58.150:4747 > 68.10.16.30:53 out > > via dc1 > > > > FWIW, these rules are skipping to: > > > > # This is skipto location for outbound stateful rules > > $cmd 800 divert natd ip from any to any out via $pif > > $cmd 801 allow ip from any to any > > > > I apologize for being such a bother and I do appreciate any help or > > suggestions. > > > > TIA > > > > Jim C. > > > > > > > > > -----Original Message----- > > > From: owner-freebsd-questions@freebsd.org > > > [mailto:owner-freebsd-questions@freebsd.org] On Behalf Of JJB > > > Sent: Friday, July 30, 2004 1:20 PM > > > To: James A. Coulter; freebsd-questions@freebsd.org > > > Subject: RE: Firewall Rule Set not allowing access to DNS > servers? > > > > > > > > > Change this ipfw rule from > > > > > > 00005 allow ip from any to any via xl0 > > > > > > To > > > 00005 allow ip from any to any via dc0 > > > > > > because dc0 is the lan interface name and not xl0. > > > > > > > > > Change these statement in rc.conf because you have interface > name > > > backwards. Dc1 is the NIC connected to your cable modem and > > you want > > > to get DHCP info from your ISP. Dc0 is the NIC connected to > > your LAN. > > > > > > From > > > ifconfig_dc1="DHCP" > > > ifconfig_dc0="inet 192.168.1.1 netmask 255.255.255.0" > > > > > > to > > > ifconfig_dc0="DHCP" > > > ifconfig_dc1="inet 192.168.1.1 netmask 255.255.255.0" > > > > > > > > > You do not say how your LAN PCs get their ip address. > > > You can hard code them on each LAN PC > > > or you have to run isc-dhcp-server on your Gateway box to > > auto assign > > > ip address to LAN PCs. > > > > > > > > > > > > > > > > > > > > > > > > -----Original Message----- > > > From: owner-freebsd-questions@freebsd.org > > > [mailto:owner-freebsd-questions@freebsd.org]On Behalf Of James > A. > > > Coulter > > > Sent: Friday, July 30, 2004 10:56 AM > > > To: freebsd-questions@freebsd.org > > > Subject: Firewall Rule Set not allowing access to DNS servers? > > > > > > I am using FreeBSD 4.10 as a gateway/router for a small > > home LAN. My > > > outside interface (dc1) is connected to a cable modem and is > > > configured for DHCP. > > > > > > I have compiled and installed a custome kernel with IPFIREWALL > and > > > IPDIVERT options and with a rule set allowing any to any with no > > > problems > > > > > > I am in the process of adding a proper rule set to provide > > security. I > > > was referred to > > http://freebsd.a1poweruser.com:6088/FBSD_firewall/ and > > > installed the Stateful + NATD Rule Set modified for my outside > > > interface, domain name servers, and DHCP server. > > > > > > I can ping IP addresses and pass SMTP mail back and forth from > the > > > gateway/router and all machines on the LAN, but I cannot > > ping URLs - I > > > am getting "ping: cannot resolve > > > www.freebsd.org: Host name lookup failure" errors. > > > > > > > > > This is what ipfw -a list looks like: > > > > > > sara# ipfw -a list > > > 00005 0 0 allow ip from any to any via xl0 > > > 00010 52 3640 allow ip from any to any via lo0 > > > 00014 0 0 divert 8668 ip from any to any in recv dc1 > > > 00015 0 0 check-state > > > 00020 0 0 skipto 800 tcp from any to 68.105.161.20 53 > > > keep-state out > > > xmit dc1 setup > > > 00021 0 0 skipto 800 tcp from any to 68.1.18.25 53 > > keep-state > > > out xmit > > > dc1 setup > > > 00022 0 0 skipto 800 tcp from any to 68.10.16.30 53 > > keep-state > > > out > > > xmit dc1 setup > > > 00030 0 0 skipto 800 udp from any to 172.19.17.22 67 > > > keep-state out > > > xmit dc1 > > > 00040 0 0 skipto 800 tcp from any to any 80 keep-state out > > > xmit dc1 > > > setup > > > 00050 0 0 skipto 800 tcp from any to any 443 keep-state > out > > > xmit dc1 > > > setup > > > 00060 0 0 skipto 800 tcp from any to any 25 keep-state out > > > xmit dc1 > > > setup > > > 00061 0 0 skipto 800 tcp from any to any 110 keep-state > out > > > xmit dc1 > > > setup > > > 00070 0 0 skipto 800 tcp from me to any uid root > keep-state > > > out xmit > > > dc1 setup > > > 00080 0 0 skipto 800 icmp from any to any keep-state out > > xmit > > > dc1 > > > 00090 0 0 skipto 800 tcp from any to any 37 keep-state out > > > xmit dc1 > > > setup > > > 00100 0 0 skipto 800 tcp from any to any 119 keep-state > out > > > xmit dc1 > > > setup > > > 00110 0 0 skipto 800 tcp from any to any 22 keep-state out > > > xmit dc1 > > > setup > > > 00120 0 0 skipto 800 tcp from any to any 43 keep-state out > > > xmit dc1 > > > setup > > > 00130 0 0 skipto 800 udp from any to any 123 keep-state > out > > > xmit dc1 > > > 00300 0 0 deny ip from 192.168.0.0/16 to any in recv dc1 > > > 00301 0 0 deny ip from 172.16.0.0/12 to any in recv dc1 > > > 00302 0 0 deny ip from 10.0.0.0/8 to any in recv dc1 > > > 00303 0 0 deny ip from 127.0.0.0/8 to any in recv dc1 > > > 00304 0 0 deny ip from 0.0.0.0/8 to any in recv dc1 > > > 00305 0 0 deny ip from 169.254.0.0/16 to any in recv dc1 > > > 00306 0 0 deny ip from 192.0.2.0/24 to any in recv dc1 > > > 00307 0 0 deny ip from 204.152.64.0/23 to any in recv dc1 > > > 00308 0 0 deny ip from 224.0.0.0/3 to any in recv dc1 > > > 00315 0 0 deny tcp from any to any 113 in recv dc1 > > > 00320 0 0 deny tcp from any to any 137 in recv dc1 > > > 00321 0 0 deny tcp from any to any 138 in recv dc1 > > > 00322 0 0 deny tcp from any to any 139 in recv dc1 > > > 00323 0 0 deny tcp from any to any 81 in recv dc1 > > > 00330 0 0 deny ip from any to any in recv dc1 frag > > > 00332 0 0 deny tcp from any to any in recv dc1 established > > > 00360 0 0 allow udp from 172.19.17.22 to any 68 keep-state > > in > > > recv dc1 > > > 00370 0 0 allow tcp from any to me 80 limit src-addr 2 in > > recv > > > dc1 > > > setup > > > 00370 0 0 allow tcp from any to me 8888 limit src-addr 2 > in > > > recv dc1 > > > setup > > > 00380 0 0 allow tcp from any to me 22 limit src-addr 2 in > > recv > > > dc1 > > > setup > > > 00400 0 0 deny log logamount 10 ip from any to any in recv > > dc1 > > > 00450 81 5288 deny log logamount 10 ip from any to any out > xmit > > dc1 > > > 00800 0 0 divert 8668 ip from any to any out xmit dc1 > > > 00801 645 59255 allow ip from any to any > > > 00999 0 0 deny log logamount 10 ip from any to any > > > 65535 1 347 deny ip from any to any > > > This is what my /etc/rc.conf looks like: > > > > > > hostname="sara.mshome.net" > > > ifconfig_dc1="DHCP" > > > ifconfig_dc0="inet 192.168.1.1 netmask 255.255.255.0" > > > firewall_enable="YES" firewall_script="/etc/ipfw.rules" > > > firewall_logging="YES" kern_securelevel_enable="NO" > > linux_enable="YES" > > > moused_enable="YES" named_enable="YES" nfs_client_enable="YES" > > > nfs_reserved_port_only="YES" nfs_server_enable="YES" > > > sendmail_enable="YES" sshd_enable="YES" usbd_enable="YES" > > > ntpd_enable="YES" inetd_enable="YES" gateway_enable="YES" > > > natd_enable="YES" natd_interface="dc1" natd_flags="-dynamic" > > > > > > Finally, this is what /etc/resolv.conf looks like: > > > > > > sara# more /etc/resolv.conf > > > search pn.at.cox.net > > > nameserver 68.105.161.20 > > > nameserver 68.1.18.25 > > > nameserver 68.10.16.30 > > > > > > Any ideas? > > > > > > Thanks, > > > > > > Jim C. > > > > > > _______________________________________________ > > > freebsd-questions@freebsd.org mailing list > > > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > > > To unsubscribe, send any mail to > > > "freebsd-questions-unsubscribe@freebsd.org" > > > > > > _______________________________________________ > > > freebsd-questions@freebsd.org mailing list > > > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > > > To unsubscribe, send any mail to > > > "freebsd-questions-unsubscribe@freebsd.org" > > > > > > > _______________________________________________ > > freebsd-questions@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > > To unsubscribe, send any mail to > > "freebsd-questions-unsubscribe@freebsd.org" > > > > > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "freebsd-questions-unsubscribe@freebsd.org" > >
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