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strange routing behaviour



Something is strange with my routing. everything routes correctly by
ip address, but when using hostnames, only some names work.

Why would routing depend on hostname? I thought only ip address
counted.

This is what I mean (long, but easy to understand):

My machine's name is twoflower.marshwiggle.net
it has from the point of view of my internal network, an ip address of
192.168.1.1 (eth0).

I run dns, which for internal requests gives the following information:

twoflower:~# host twoflower
twoflower.marshwiggle.net       A       192.168.1.1
twoflower:~# host ns
ns.marshwiggle.net      A       192.168.1.1
twoflower:~# host mail
mail.marshwiggle.net    A       198.168.1.1
twoflower:~# host 192.168.1.1
Name: twoflower.marshwiggle.net
Address: 192.168.1.1
Aliases: twoflower

this is my routing table:

twoflower:~# route
Kernel IP routing table
Destination Gateway         Genmask       Flags Metric Ref Use Iface
203.87.20.0 *               255.255.255.0 U     0      0   0   eth1
192.168.1.0 *               255.255.255.0 U     0      0   0   eth0
default     ADSL-175.cust20 0.0.0.0       UG    0      0   0   eth1

If I run traceroute, this is what happens:

twoflower:~# traceroute 192.168.1.1
traceroute to 192.168.1.1 (192.168.1.1), 30 hops max, 38 byte packets
 1  twoflower (192.168.1.1)  0.260 ms  0.145 ms  0.066 ms
twoflower:~# traceroute twoflower
traceroute to twoflower (192.168.1.1), 30 hops max, 38 byte packets
 1  twoflower (192.168.1.1)  0.308 ms  0.098 ms  0.065 ms
twoflower:~# traceroute ns
traceroute to ns (192.168.1.1), 30 hops max, 38 byte packets
 1  twoflower (192.168.1.1)  0.240 ms  0.102 ms  0.074 ms

So far, so good, but when I run traceroute on mail:

twoflower:~# traceroute mail
traceroute to mail (198.168.1.1), 30 hops max, 38 byte packets
 1  Serial1-1-0.way14.telstra.net (139.130.155.13)
 2  GigabitEthernet1-0.way-core4.Adelaide.telstra.net (203.50.120.4)
 3  Pos5-0.exi-core1.Melbourne.telstra.net (203.50.6.161)
 4  Pos6-0.chw-core2.Sydney.telstra.net (203.50.6.17)
 5  10GigabitEthernet3-0.pad-core5.Sydney.telstra.net (203.50.6.90)
 6  GigabitEthernet0-0.syd-core02.Sydney.net.reach.com (203.50.13.250)
 7  GigabitEthernet1-1.syd-core01.net.reach.com (202.84.219.213)
 8  i-13-0.sjc-core01.net.reach.com (202.84.143.17)
 9  202.84.143.249 (202.84.143.249)
10  500.POS5-0.GW6.PAO1.ALTER.NET (208.214.143.177)
11  0.so-0-2-0.XL1.PAO1.ALTER.NET (152.63.55.10)
12  * * *
.
.
.
etc

All external ip address and hostnames route correctly.
Exactly the same behaviour occurs when other machines on my internal
network try to contact mail.marshwiggle.net

what is going on here?

cheers

dc

-- 
David Purton
dcpurton@chariot.net.au

If you, O LORD, kept a record of sins, O Lord, who could stand?
					Psalm 130:3



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