TCP alias problem

[Bill Campbell]

I'm having a very ``interesting'' problem with a Caldera eDesktop 2.4
system that's causing problems with NFS mounts from Apple iMacs running OS
X.  Looking at tcpdump output I see the NFS request from the Mac going to
the primary interface, eth0, on the NIC, but the response is going back
from Caldera box from another interface, eth0:3.  The Mac doesn't see this
as an appropriate reply since it's coming from the wrong IP address, hence
the mount fails.  I have manually mounted using the IP address of eth0:3
which allows the mount to succeed, but there are other problems.

I've tried ssh to various systems on the LAN, and they also appear to
originate from the eth0:3 interface.  On the other hand, I've tried ssh via
an IPSec VPN tunnel to our private network here, and the IP address comes
back as eth0.

Why would outgoing connections and replies appear to originate from the
aliased interface instead of from eth0?

Bill
--
INTERNET:   bill at Celestial.COM  Bill Campbell; Celestial Software LLC
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URL: http://www.celestial.com/

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eth0      Link encap:Ethernet  HWaddr 00:02:55:7C:E9:31  
          inet addr:192.168.254.3  Bcast:192.168.254.255  Mask:255.255.255.0
          UP BROADCAST RUNNING PROMISC MULTICAST  MTU:1500  Metric:1
          RX packets:163969377 errors:1 dropped:0 overruns:0 frame:1
          TX packets:121893031 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          Interrupt:27 Base address:0x2000 

eth0:0    Link encap:Ethernet  HWaddr 00:02:55:7C:E9:31  
          inet addr:192.168.254.13  Bcast:192.168.254.255  Mask:255.255.255.0
          UP BROADCAST RUNNING PROMISC MULTICAST  MTU:1500  Metric:1
          Interrupt:27 Base address:0x2000 

eth0:1    Link encap:Ethernet  HWaddr 00:02:55:7C:E9:31  
          inet addr:192.168.254.14  Bcast:192.168.254.255  Mask:255.255.255.0
          UP BROADCAST RUNNING PROMISC MULTICAST  MTU:1500  Metric:1
          Interrupt:27 Base address:0x2000 

eth0:2    Link encap:Ethernet  HWaddr 00:02:55:7C:E9:31  
          inet addr:192.168.254.15  Bcast:192.168.254.255  Mask:255.255.255.0
          UP BROADCAST RUNNING PROMISC MULTICAST  MTU:1500  Metric:1
          Interrupt:27 Base address:0x2000 

eth0:3    Link encap:Ethernet  HWaddr 00:02:55:7C:E9:31  
          inet addr:192.168.254.16  Bcast:192.168.254.255  Mask:255.255.255.0
          UP BROADCAST RUNNING PROMISC MULTICAST  MTU:1500  Metric:1
          Interrupt:27 Base address:0x2000 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:3924  Metric:1
          RX packets:8518928 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8518928 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0