Re: Can't access aliased ip address
> Chad,
>
> It sounds like you've fallen prey to the perils of assymmetric
> routing. For simplicity, I'll refer to your ("my machine") external
> server
> to be machine A, eth0 to be ip-address B, and eth0:1 to be ip-address C.
> Here is how things are happening :
>
> Machine A sends echo request to C.
>
> C replies. The routing table on your multihomed server says that
> the packet needs to travel out via eth0. The outgoing echo reply
> therefore
> will contain the source address of B.
>
> A is not listening for replies from B. It is listening for
> replies
> from C. Hence your problem.
>
> To see if I am right, filter tcpdump on the icmp protocol, rather
> than the host of C. If you see echo replies from B coming in, and echo
> requests for C going out, what I said is correct.
>
> Regards,
> Jor-el
>
>
This doesn't appear to be the problem. When I ping ip address C, from
machine A (my computer at a remote location) tcpdump icmp -i eth0 yields
only a request.
However, once I ping ip address B from Machine A it will show both the
request and the reply.
Also, I just looked at the syslog, which I probably should've done earlier
and found the following:
Jan 2 15:23:46 hostname kernel: Packet log: input DENY eth0 PROTO=1
MACHINEA:8 IPADDRC:0 L=92 S=0x00 I=0 F=0x4000 T=43 (#9)
Should I be looking at the firewall as the cause of the problem. However
temporarily using
ipchains -P input ACCEPT and ipchains -P output ACCEPT before going back to
the regular firewall settings gave me the exact same result. Do I need to
specifically specifiy IP Address C in the firewall script or am I chasing a
dead end?
Chad
Reply to: