Date: Sun, 27 Jul 2003 19:08:46 +0100 From: "Company 2210" <company2210@hotmail.com> To: <freebsd-questions@freebsd.org> Subject: ARP Problem - Please Help Message-ID: <Law12-OE51A9KxLt3zP000066af@hotmail.com>
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Hi, My problem is this (and it's driving me nuts as I can't see the solution). I have two freebsd boxes acting as routers, the layout is like this: Clients (12.20.78.0/25) <----->(eth0) ROUTER A (eth1)<=======> (eth1) ROUTER B (eth0) <----> (12.20.65.69) Upstream ISP & Internet Router A Configuration: eth0: 12.20.78.1 Subnet 255.255.255.128 eth1: 10.0.0.1 Subnet 255.255.255.0 Router B Configuration: eth0: 12.20.65.70 Subnet 255.255.255.252 eth1: 10.0.0.2 Subnet 255.255.255.0 The private IP's denote an IPSEC VPN connection (Wireless) between ROUTER A & B, all the client PC's are on public IP's. Now, the VPN works perfectly, encrypting the packets over the wireless link, however ROUTER A's eth0 interface does not appear in the arp -a lookup: ? (10.0.0.1) at 00:05:5d:a6:15:78 on eth1 permanent [ethernet] ? (10.0.0.2) at 00:c0:dd:ea:ac:5c on eth1 [ethernet] ? (12.20.78.0) at ff:ff:ff:ff:ff:ff on eth0 permanent [ethernet] ? (12.20.78.2) at 00:0c:cd:53:d9:f3 on eth0 [ethernet] ? (12.20.78.42) at 00:9a:17:90:d3:b4 on eth0 [ethernet] ? (12.20.78.52) at 00:2b:18:2e:22:21 on eth0 [ethernet] ? (12.20.78.127) at ff:ff:ff:ff:ff:ff on eth0 permanent [ethernet] If I try and force the entry, I receive the following error: routera# arp -s 12.20.78.1 00:0c:5d:e6:16:75 set: can only proxy for 12.20.78.1 The big problem this is causing is that clients cannot ping the gateway, and it responds to no requests (i.e I can't ssh into it), but it still forwards packets perfectly. Basically it's like 12.20.78.1 was invisible. The other strange thing is, that if I ssh into ROUTER B and ping 12.20.78.1 I receive replies: routerb# ping 12.20.78.1 PING 12.20.78.1 (12.20.78.1): 56 data bytes 64 bytes from 12.20.78.1: icmp_seq=0 ttl=64 time=3.577 ms 64 bytes from 12.20.78.1: icmp_seq=1 ttl=64 time=3.724 ms 64 bytes from 12.20.78.1: icmp_seq=2 ttl=64 time=3.817 ms ^C --- 12.20.78.1 ping statistics --- 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max/stddev = 3.577/3.706/3.817/0.099 ms The output of ROUTER B's arp table is displayed below: ? (10.0.0.1) at 00:05:5d:a6:15:78 on eth1 [ethernet] ? (10.0.0.2) at 00:c0:dd:ea:ac:5c on eth1 permanent [ethernet] ? (12.20.65.69) at 00:d0:03:ba:bb:fc on eth0 [ethernet] I am completely at a loss as to how to get around this problem. Any help or advice would be really great as I've spend the past 3 days, and the floor is littered with tufts of hair ;) Just incase this is any help, this is the output from setkey -DP (For encrypting the packets across the 10.0.0.x link) on each router: ROUTER A: 0.0.0.0/0[any] 12.20.78.0/25[any] any in ipsec esp/tunnel/10.0.0.2-10.0.0.1/require spid=2 seq=1 pid=778 refcnt=1 12.20.78.0/25[any] 0.0.0.0/0[any] any out ipsec esp/tunnel/10.0.0.1-10.0.0.2/require spid=1 seq=0 pid=778 refcnt=1 ROUTER B: 12.20.78.0/25[any] 0.0.0.0/0[any] any in ipsec esp/tunnel/10.0.0.1-10.0.0.2/require spid=8 seq=1 pid=24377 refcnt=1 0.0.0.0/0[any] 12.20.78.0/25[any] any out ipsec esp/tunnel/10.0.0.2-10.0.0.1/require spid=7 seq=0 pid=24377 refcnt=1 Please help!!! :)) Many Thanks Colin Watson (Nearly bald guy)
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