CentOS - Jul 2015 - Multiple network cards - routing issue?

I have a Centos 5 machine here that, up until about a year ago, was happily
running Icecast and serving streaming audio through through three network
connections, consisting of one "local" connection (local address
192.168.1.5)  and two cable modems to talk to the outside world.

We shut this down about a year ago, but now I am attempting to get it going
again on one outside connection instead of two.  Simply changing the IP address
on one of the network cards to use the new address isn't working, so the
notes that I made when I set this thing up in the first place must be incomplete
since I'm obviously missing something here.

I have two "active" IP addresses that I want to use at the moment.

 eth0 is 192.168.1.5 and is working fine.  I can log into the server with ssh
and run icecast and listen to streaming audio just fine.

eth1 is now supposed to be 204.83.105.1 so I configured the new address on that
card with system-config-network.

The third card (eth2) I plan to ignore for the time being so I haven't
changed that or done anything with it at all.

My /etc/iproute2/rt_tables looks like this.  I haven't changed it from what
it was when I originally set this thing up a few years ago.

#
# reserved values
#
255     local
254     main
253     default
0       unspec
#
# local
#
#1      inr.ruhep
50      access1
60      access2

Note the access1 and access2 entries at the bottom of the file.

I then ran the following three commands:

ip route add 204.83.15.0/24 dev eth1 table access1
ip route add default via 204.83.15.254 dev eth1 table access1
ip rule add from 204.83.15.1/32 lookup access1

These are the same commands that I used to set up the previous Internet
connection on this server -- The only thing that I have changed was the IP
addresses.

Here is the output from "ip route show":

[root at audio ~]# ip route show
192.168.1.0/24 dev eth0  proto kernel  scope link  src 192.168.1.5 
204.83.15.0/24 dev eth1  proto kernel  scope link  src 204.83.15.1 
169.254.0.0/16 dev eth1  scope link 
default via 204.83.15.254 dev eth1 

That seems to indicate that the default route is 204.83.15.254 which is the
correct gateway number for that Internet connection.

However, a ping or traceroute command (ping google.com or whatever) gives me no
output.

I've missed a step somewhere.

I hooked my laptop up to that Internet connection to insure that the modem and
whatnot is working and it is, so there's obviously something wrong with my
configuration.

Can any of you folks tell me what I've missed?

-- 
MELVILLE THEATRE ~ Real D 3D Digital Cinema ~ www.melvilletheatre.com

On Sat, 18 Jul 2015 11:41:53 -0600
Frank Cox wrote:
 output.
> 
> I've missed a step somewhere.
> 
> I hooked my laptop up to that Internet connection to insure that the modem
> and whatnot is working and it is, so there's obviously something wrong
with
> my configuration.
> 
> Can any of you folks tell me what I've missed?
Here's something interesting.

When I run a traceroute to 204.83.15.254 I get this:

[frankcox at audio ~]$ traceroute 204.83.15.254
traceroute to 204.83.15.254 (204.83.15.254), 30 hops max, 40 byte packets
 1   (204.83.15.1)  3000.077 ms !H  3000.068 ms !H  3000.052 ms !H

It thinks that 204.83.15.254 is down, and that's the gateway address for
eth1 that I want to be the default gateway.

And 192.168.1.1 is the address of the router that eth0 is plugged into:

[frankcox at audio network-scripts]$ ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
--- 192.168.1.1 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 1999ms

I can ssh into the server through that router (and eth0) with no problem. 
That's how I'm communicating with it right now.

[frankcox at audio network-scripts]$ /sbin/route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0
204.83.15.0     0.0.0.0         255.255.255.0   U     0      0        0 eth1
169.254.0.0     0.0.0.0         255.255.0.0     U     0      0        0 eth1
0.0.0.0         204.83.15.254   0.0.0.0         UG    0      0        0 eth1


-- 
MELVILLE THEATRE ~ Real D 3D Digital Cinema ~ www.melvilletheatre.com

On 07/18/2015 10:41 AM, Frank Cox wrote:
> I then ran the following three commands:
>
> ip route add 204.83.15.0/24 dev eth1 table access1
> ip route add default via 204.83.15.254 dev eth1 table access1
> ip rule add from 204.83.15.1/32 lookup access1
...
> Can any of you folks tell me what I've missed?
Does the system work correctly if you don't run those "ip route"
commands?

On Sat, 18 Jul 2015 21:34:27 -0700
Gordon Messmer wrote:
> Does the system work correctly if you don't run those "ip
route" commands?
It's exactly the same.  And what I mean by exactly the same is EXACTLY the
same.

I rebooted the system which should clear out my route commands and whatnot, and
discovered that everything (route -n and ip route show and whatnot) are exactly
the same as before.  Therefore, the ip route and ip rule commands apparently had
no effect whatsoever -- what I got after entering the ip route commands is
exactly what I have without entering those commands.

Interesting.  But since it's still exactly the same, it's still not
working; it still fails in exactly the same way too.

-- 
MELVILLE THEATRE ~ Real D 3D Digital Cinema ~ www.melvilletheatre.com