Problems with routing on 11.11i

[Jeffrey Mulliken]

Hello network wizards, I hope that you can help me. Something has happened to my system and I can't figure out what. Perhaps there's something wrong with my routing tables, but I can't see what it is. I include the slightly edited output of a 'netstat -r' below for review.

I can navigate my local subnet just fine, but when I try to get to anywhere outside, I get the "no route to host" error. For example, I can do an 'nslookup' for a remote host, and that will output the correct IP address for that machine, so DNS are working, (but the server is on my local subnet, so that's no big surprise) but when I then try to telnet to that host..."no route to host".

Another symptom that I have that may, or may not, be related... I was having trouble getting configured as an NIS client, and when I would try to use the SAM facility for configuring a NIS client, a message window would pop up saying something to the effect of "This version of SAM is not able to configure NIS under IPV6". Well, to the best of my knowledge, I'm not running IPV6, so why would I get that message? The NFS setup function does the same thing.

Any ideas and/or suggestions offered will be appreciated. Cheers, Jeff Mulliken

root:/ $netstat -r
Routing tables
Destination Gateway Flags Refs Interface Pmtu
localhost localhost UH 0 lo0 4136
ducati ducati UH 0 lan0 4136
XXX.XX.80.0 ducati U 2 lan0 1500
127.0.0.0 localhost U 0 lo0 0
default XXX.XX.80.1 UG 0 lan0 0

[Mel Burslan]

first question :

can you ping your default gateway from this box, i.e. :

ping XXX.XX.80.1

is it working ?

if not, you may need help from your networking group to put a trace on the physical route to see what is wrong.

[Jeffrey Mulliken]

Mel,

Thanks for the reply. I can not ping the gateway, but that's to be expected, as it's a Cicso box, and will not respond to a ping. None of the servers in the subnet can ping the gateway. But I can telnet into this server from outside the subnet, so the gateway is working, but just not the other way around. Thanks again for the response. Jeff.

[Mel Burslan]

ifconfig lan0

then try pinging the IP address presented by this command for your interface, i.e., let it ping itself and see what kind of message you are gtting, if any ?

ps. going home... response may be delayed but I am sure there will be other people to see your responses and jump for help meanwhile.

also, can you telnet to this cisco router at ip address XXX.XX.80.1 and ger a username or password prompt ?

[Jan Sladky]

hi Jeff,

your routing table seems ok, you say the gateway is working, strange ...

try telnet (or another way - nmap scanner how to contact default gw), is it responding ?

what about to try ethereal ?
(http://hpux.cs.utah.edu/hppd/hpux/Gtk/Applications/ethereal-0.9.15/)
use it and see on communication between your machine and gw

from !system konsole! you can also try ifconfig down/up lan0

post the the results

br Jan

[Duncan Edmonstone]

If you can't ping (ICMP echo request) your default gateway then the 'dead gateway detection' algorithm built into the IP stack on HP-UX will detect this fact and mark the gateways as 'dead'. This is probably what has happened here. You can check this using:

ndd -get /dev/ip/ip_ire_status

Locate the routing line for your gateway and see if it is marked as dead.

You can override this using the following command:

ndd -set /dev/ip ip_ire_gw_probe 0

This turns off dead gateway detection. Make the change permanent across reboots by editing /etc/rc.config.d/nddconf (the files pretty much self explanatory).

HTH

Duncan

[jeffrey Mulliken_1]

Duncan,

Good call! You nailed it. And it is now fixed. Thanks very much to you, and all of the others who tried to help. Cheers,

Jeff.

[Ron Kinner · Accepted solution]

Jeff,

Not "Cheers" but points! Duncan's answer was right on and he should get 10 points for it.

Ron

[Jeffrey Mulliken]

Ron,

Thanks for pointing out my oversight. I didn't fully understand how the forum thing worked. Now I'm clued in. My appologies to those above who were overlooked originally in the point distribution. Thanks, Jeff.