Once upon a time, Gordon Smith <[email protected]> said: > Put the /32 on a loopback instead of a secondary address.
Um, I did that (as I said at the end of the email). It didn't change anything. > You could always fire up WireShark and watch exactly what's going on on > the wire That's how I got all the info; I ran tcpdump on the Linux server and "monitor traffic interface me0" (which is really tcpdump) on the EX. Both sides see the same packets; the EX just doesn't respond to the ARP requests. -- Chris Adams <[email protected]> Systems and Network Administrator - HiWAAY Internet Services I don't speak for anybody but myself - that's enough trouble. > On Wed, 9 Mar 2011 18:56:44 -0600, Chris Adams wrote: > >Once upon a time, Gordon Smith <[email protected]> said: > >>Check the default router config. > >> > >>When the server sends the arp request, the router should reply with > >>it's own MAC address > >>Does it not have a route back to the switch? > > > >No, the router isn't proxy ARPing. Let me put some IPs to the > >problem: > > > >EX switch: 10.1.1.5/27 > >Linux server eth0: 10.1.1.10/27 > >router (M10i): 10.1.1.30/27 > >DNS IP: 10.2.2.2/32 (secondary IP on Linux server eth0) > > > >EX wants to reach 10.2.2.2, so it sends the packet to the M10i at > >10.1.1.30. Router has route for 10.2.2.2/32 pointing to 10.1.1.10, > >so > >it sends the packet to the Linux server. Linux server realizes it > >doesn't need to route back to EX in the same subnet and is going to > >send > >a packet directly from 10.2.2.2 to 10.1.1.5. Linux server doesn't > >have > >an ARP entry for 10.1.1.5, so it sends an ARP request, using a source > >IP > >of 10.2.2.2 (since that's the source of the desired packet). > > > >At this point the EX sees the ARP request for its IP, but doesn't > >respond to it. I'm guessing it is ignoring the ARP request because > >the > >source IP is in a different subnet (but that's just a guess). > > > >There's also an old Cisco switch on the same segment, and it replies > >to > >out-of-subnet ARP requests just fine. I also tried a FreeBSD host in > >a > >similar setup with a different Linux server, and it also works okay. > >I > >don't have any other OSes handy to try. > > > >Per another email, I tried setting the Linux server to put the DNS IP > >on > >a loopback interface instead of the ethernet, but it still sent the > >ARP > >request with the DNS IP as the source. _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
