Support LQ: Use code LQ3 and save $3 on Domain Registration
Go Back > Forums > Linux Forums > Linux - Networking
User Name
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.


  Search this Thread
Old 07-07-2011, 05:17 PM   #1
LQ Newbie
Registered: Oct 2005
Posts: 7

Rep: Reputation: 0
need to populate arp dynamically

I've got a bit of a weird situation I think -- running Ubuntu 9.04

I've got a dev machine where we've set up multihoming via this in the interfaces file:

auto eth0:1
iface eth0:1 inet static

so that we can have multiple https hosts.

When we first set this up, other machines on our corporate network could not see ping the address, even though they could ping the main address for this machine. (they get this error: 92 bytes from Destination Host Unreachable)

after executing this command:
route add -host dev eth0:1
and then

other machines on the network could then ping the address just fine.

I concluded that there was an arp problem, and so I set up a periodic ping in case the arp cache got flushed (I did this after it got flushed one time, and we lost connectivity again).

This all seems like a huge hack to me, with the right solution being to modify the arp settings or something (although it seems like it is probably generally set up dynamically).

recently the network architecture at my work changed (I don't have any control over that, I just need my server to work), and now my ping solution isn't working -- any ideas?

Thanks much
Old 07-10-2011, 10:53 PM   #2
Senior Member
Registered: Aug 2009
Posts: 3,790

Rep: Reputation: 650Reputation: 650Reputation: 650Reputation: 650Reputation: 650Reputation: 650
It may be worth trying a packet sniffer (tcpdump, wireshark) to see what's really going on.
1 members found this post helpful.
Old 07-11-2011, 03:51 PM   #3
LQ Guru
Registered: Mar 2008
Posts: 13,492

Rep: Reputation: 1717Reputation: 1717Reputation: 1717Reputation: 1717Reputation: 1717Reputation: 1717Reputation: 1717Reputation: 1717Reputation: 1717Reputation: 1717Reputation: 1717
Nic's chatter all the time. They send out arp requests and hold them for a time. You don't populate it dynamically. It is done automatically. You populate static by command if you want it there for longer times.

If you have a switch it may hold the arp page for a long time and you may be able to hold it there forever even depending on model.
1 members found this post helpful.
Old 07-11-2011, 03:57 PM   #4
LQ Newbie
Registered: Oct 2005
Posts: 7

Original Poster
Rep: Reputation: 0
Thanks much both of you -- I'm not very familiar with ARP, but suspected it was supposed to work automatically. Am investigating what is going on further (thanks for the tcpdump / wireshark suggestion, I've used them before for other issues, but for some reason didn't think to use it here, so


arp, multihomed, route

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Strange ARP behavior : A linux server responds to all ARP requests Hdvd21 Linux - Networking 4 10-24-2013 05:02 AM
arp poisoning vs arp spoofing sulekha Linux - Networking 1 05-13-2009 04:22 AM
Disabling ARP probes after receiving an ARP request AltecLansingMan Linux - Networking 1 03-30-2004 01:25 PM
Populate the HCL finegan Linux - Hardware 0 11-06-2003 07:34 PM
How to create an proxyarp entry in arp table by using arp command? himalayas Linux - Networking 0 06-04-2003 04:14 AM

All times are GMT -5. The time now is 05:23 AM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration