Date: Tue, 13 Mar 2001 23:32:58 +0530 (IST) From: Satyajeet Seth <sseth@sasken.com> To: Julian Elischer <julian@elischer.org> Cc: <net@freebsd.org>, <gbnaidu@sasken.com> Subject: Re: Ping Problem Message-ID: <Pine.GSO.4.30.0103132112480.24779-100000@suns3.sasi.com> In-Reply-To: <3AACD88F.71BCAFEC@elischer.org>
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Hi Please see my comments below. > > I am using FreeBSD 4.1. I followed Roger's suggestion about "autosrc 0" > > message. But "autosrc" message is not available in ng_ether. > > I have tried commenting > > bcopy((IFP2AC(priv->ifp))->ac_enaddr, eh->ether_shost, > > 6); > > in ng_ether_rcv_lower in ng_ether.c with the effect that fxp0 is able to > > send packets with pseudo ethernet interface MAC address. > > please upgrade to at least 4.1.1 which has the autosrc command. > preferably to 4.2. If you need to maybe look at upgrading just netgraph > and possibly if_ethersubr.c bit I would be happier to see a move up for > the system as a whole. > > An upgrade within the '4' family should be pretty painless. I tried using a FreeBSD4.1.1 system, but the problem is still there. I suppose for now, my hack on FreeBSD4.1 will serve the purpose. Am I correct? > > > > I have tried the following setup for pinging from nge0 to some machine on > > LAN. > > > > on pcs130 (Machine with pseudo ethernet interfaces, see output of > > "ifconfig -a" below) > > ============================== > > 1. #route change -host 10.0.36.134 -ifp nge0 > > Now arp starts to print messages like: > > arp: 'IP addr' is on fxp0 but got response from 'MAC address' on nge0. > > broadcast frames received have to be sent to the interface that > is on that net. To do this you would need to read arp packets to decide > which network to send it. (sinc ethey are the usual users of broadcast > messages. At the moment you MAY MAY have success if you enable some bridging > as that disables some of those checks. > I tried putting 'options BRIDGE' in my configuration file. But now ARP resolution of pseudo ethernet interface returned MAC address of fxp0. So I reverted back. > > > > 2. #ping 10.0.36.134 > > This does not work. > > probably the arp packets are never getting back to the right interface > > You need to do more packet tracing. > does the packet hit the wire? Yes > does the target respond? Yes > is there a arp packet before it? Yes > does the dest respond tothe arp? Yes > does the response appear in the arp table? Yes > does the destination in turn send an arp request before responding to the ping? No. > does the arp response (broadcast) get assigned to an interface? > does it get answered? > from which interface? > does the response hit the wire? The answer to above three queries is no, because destination does not in turn send an arp request before responding to the ping. The ICMP request packets are reaching pseudo ethernet interface. But it is not responding back. This happens even if an ARP entry for the destination is there. Could you suggest what could be the problem? > > It was never envisionned to multiplex multiple ether networks over a single > network without adding a layer e.g. VLAN. This is what VLAN is for. > > The problems with broadcast packets is one of the problems. > > > > > on pcs134(some machine on lan) > > ============================== > > Using tee's I found that 10.0.36.134 receives ethernet frames with src > > MAC address of nge0 and dest MAC address of 10.0.36.134. > > pcs134 response frames are sent to MAC address of default router > > 10.0.32.1. But pcs130 does not receive these frames. > > why does the PC send to the default router? netmask problems I think > mask == ffffffff is probably a problem. Setting the same mask as fxp0 helps. My current ifconfig setting are: #ifconfig -a fxp0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 150 0 inet 10.0.36.130 netmask 0xfffff000 broadcast 10.0.47.255 inet6 fe80::2d0:b7ff:febd:711%fxp0 prefixlen 64 scopeid 0x1 ether 00:d0:b7:bd:07:11 media: autoselect (100baseTX <full-duplex>) status: active supported media: autoselect 100baseTX <full-duplex> 100baseTX 10 baseT/UTP <full-duplex> 10baseT/UTP lp0: flags=8810<POINTOPOINT,SIMPLEX,MULTICAST> mtu 1500 sl0: flags=c010<POINTOPOINT,LINK2,MULTICAST> mtu 552 faith0: flags=8000<MULTICAST> mtu 1500 gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280 gif1: flags=8010<POINTOPOINT,MULTICAST> mtu 1280 gif2: flags=8010<POINTOPOINT,MULTICAST> mtu 1280 gif3: flags=8010<POINTOPOINT,MULTICAST> mtu 1280 lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384 inet6 fe80::1%lo0 prefixlen 64 scopeid 0x9 inet6 ::1 prefixlen 128 inet 127.0.0.1 netmask 0xff000000 ppp0: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 nge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet 10.0.36.157 netmask 0xfffff000 broadcast 10.0.47.255 inet6 fe80::211:22ff:fe33:4455%nge0 prefixlen 64 scopeid 0xb ether 00:11:22:33:44:55 nge1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet 10.0.36.158 netmask 0xfffff000 broadcast 10.0.47.255 inet6 fe80::2d0:b7ff:febd:711%nge1 prefixlen 64 scopeid 0xc ether 11:22:33:44:55:66 Thanks Satya To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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