topic Re: traceroute difference with routing table?!? in Operating System - HP-UX

traceroute difference with routing table?!?

Emanuele_4 — Mon, 26 Jul 2004 07:56:23 GMT

Hi everybody!

I've a strange problem: when I traceroute a server on the same primary network the HPUX11.i system uses the SECONDARY network!

I check out netconf and everything seems currect but when I traceroute...it's wrong.

Here is the netconf file:

INTERFACE_NAME[0]="lan0"
IP_ADDRESS[0]="128.101.0.8"
SUBNET_MASK[0]="255.255.0.0"
BROADCAST_ADDRESS[0]=""
INTERFACE_STATE[0]=""
DHCP_ENABLE[0]=0

INTERFACE_NAME[1]=lan1
IP_ADDRESS[1]=192.168.0.11
SUBNET_MASK[1]=255.255.255.0
BROADCAST_ADDRESS[1]=192.168.0.255
INTERFACE_STATE[1]=up
DHCP_ENABLE[0]=0

ROUTE_DESTINATION[0]="default"
ROUTE_MASK[0]=""
ROUTE_GATEWAY[0]="128.101.0.30"
ROUTE_COUNT[0]="1"
ROUTE_ARGS[0]=""

Here is the netstat -rnv output

Dest/Netmask Gateway Flags Refs Interface Pmtu
127.0.0.1/255.255.255.255 127.0.0.1 UH 0 lo0 4136
128.101.0.8/255.255.255.255 128.101.0.8 UH 0 lan0 4136
192.168.0.11/255.255.255.255 192.168.0.11 UH 0 lan1 4136
192.168.0.0/255.255.255.0 192.168.0.11 U 2 lan1 1500
128.101.0.0/255.255.0.0 128.101.0.8 U 2 lan0 1500
127.0.0.0/255.0.0.0 127.0.0.1 U 0 lo0 0
default/0.0.0.0 128.101.0.30 UG 0 lan0 0

FINALLY....the traceroute output:

traceroute 128.101.0.1
traceroute: Warning: Multiple interfaces found; using 192.168.0.11 @ lan1
traceroute to 128.101.0.1 (128.101.0.1), 30 hops max, 40 byte packets
1 * * *
2 * * *
3 * * *

and the correct traceroute (I give him the correct source NIC):

traceroute -s 128.101.0.8 128.101.0.1
traceroute to 128.101.0.1 (128.101.0.1) from 128.101.0.8, 30 hops max, 40 byte p
ackets
1 pbitlmux (128.101.0.1) 5.965 ms 5.830 ms 5.736 ms
pbpchrux:root: /etc/rc.config.d#

******
I'd like that the server (128.101.0.8) will reach the remote server (128.101.0.1) with the primary network (128.101.0.0 255.255.0.0) and not by the secondary network (192.168.0.0 255.255.255.0)

Does anybody know where I'm getting wrong?

Thanks in advance to anybody!

Emanuele

Re: traceroute difference with routing table?!?

Steven E. Protter — Mon, 26 Jul 2004 09:02:06 GMT

lan1 just because its the second interface is not necessarily not the primary.

During install there is a box you can check to designate a primary interface. That makes a change to the netconf file.

This is probably a function of the default route, though it could be affected by where the DNS server is. If the DNS server is only reachable via lan1, that explains the behavior.

What is in /etc/resolv.conf

SEP

Re: traceroute difference with routing table?!?

Steve Lewis — Mon, 26 Jul 2004 09:07:08 GMT

Emanuele,

Traceroute on 11i does not work the same as it did in 11.00 (or 10.xx) or the same as MS windows. It is one of the few command changes from 11.00 to 11i.

Previously it would work out which interface to use for an IP you give it. Nowadays it isn't so clever.

To traceroute in 11i, you need to specify either the source interface using traceroute -i 0 128.101.0.1
or the command you specified, traceroute -s.

Your traceroute -s output shows that the server does have a route to the IP you gave. You have done nothing wrong that I can see.

Do you have a connectivity issue? If so, the problem may lie elsewhere.

Re: traceroute difference with routing table?!?

Emanuele_4 — Mon, 26 Jul 2004 10:28:46 GMT

uhmm....I haven't any resolv.conf under /etc...very strange (even my debian box has it!).

Anyway...can I make lan0 the default (primary) lan to use?

Thanks again to everybody!

Re: traceroute difference with routing table?!?

Fred Ruffet — Mon, 26 Jul 2004 10:58:58 GMT

Emanuele,

Try to use "ping -o" instead of "traceroute". I already had problems with 2 cards and traceroute. Ping -o gets info from where the ICMP packets come back. It will show you the real route, whereas traceroute seems to use a default card wich is not always the good one.

Regards,

Fred

Re: traceroute difference with routing table?!?

Fadia Almarei — Tue, 27 Jul 2004 00:50:56 GMT

Hi
i have an idea , if you want you can reconfigure the network connection in your server what you do as the following
1-rename the netconf file
#mv /etc/rc.config.d/netconf /etc/rc.config.d/netconf
2- get an empty netconf file
#cd /usr/newconfig/etc/rc.config.d
#cp netconf /etc/rc.config.d/netconf
3-then reconfigure your network
#set_parms
4-after that you can see GUE from which you can configure your network

Re: traceroute difference with routing table?!?

Brian Hackley — Tue, 27 Jul 2004 08:25:36 GMT

Folks,
This question comes up as an 11.11 FAQ issue. I went and checked to see if a bug fix has ever been created for traceroute.
I thought you all should know this info:

The HP Transport Lab has this Service Request 8606356802:
"As of 11.11 traceroute command is broken." CR # JAGaf17502

Present plan is to update the traceroute command in a future 11.11 ARPA Transport patch presently slated for late 2004 or early 2005.

Fix consists of initializing IP source address in IP header to
0.0.0.0 before sending the packet down to IP through rawip socket
letting IP choose the appropriate source address based on the
routing table when neither '-i' nor '-s' options are specified.

I'll also point out a usage note, when using -i, you need to say "lan0" not just the interface PPA number.

Hope that helps,
-> Brian Hackley