2008-07-24 00:04:00     dual network interface issue

Document created by Aaronwu Employee on Aug 7, 2013
Version 1Show Document
  • View in full screen mode

2008-07-24 00:04:00     dual network interface issue

Tinku Jose (INDIA)

Message: 59299   

 

Hi,

 

We are facing an issue while enabling 2 network interfaces in uClinux. (we are using 2007R1)

 

The issues is as follows.

 

enable eth0 with IP 'a', MAC address is 'x'

 

enable eth1 with IP 'b', MAC address is 'y'

 

In this mode both 'a' and 'b' can be pinged from the PC and the arp tables show proper values

 

bring down eth0

 

clear the arp tables in the PC

 

ping 'b' from PC and it works

 

ping 'a' from PC, it also works!!!! (whereas it should not have, as eth0 is down)

 

if you check the arp tables it is observed that both 'a' and 'b' are mapped to same MAC address, that is of 'b' which is 'y'

 

if the same experiment is done with disabling eth1 instead of eth0,

 

the arp tables are having the MAC address of 'a' which is 'x' for both 'a' and 'b'

 

 

 

Have any issues similar to this observed? Please let me know if there are any know issues or is it any configuration problem and what are the solutions

 

currently the only option we are having is to set the ip address of the interface which is brought down to 0.0.0.0.

 

 

 

thanks in advance

 

best regards

 

tinku

QuoteReplyEditDelete

 

 

2008-07-24 00:17:32     Re: dual network interface issue

Mike Frysinger (UNITED STATES)

Message: 59300   

 

this is expected default behavior.  Linux will respond to any IPs it has on any interface.  bringing down an interface does not unbind the associated IPs, it just means the interface will not be used.  if you want to unbind an IP, then you need to do so explicitly.

QuoteReplyEditDelete

 

 

2008-07-24 01:52:26     Re: dual network interface issue

Tinku Jose (INDIA)

Message: 59302   

 

Hi Mike,

 

But when a interface is brought down, is the IP address associated with that interface be reachable? As i mentioned,

 

when eth0 is down, still we are able to ping to the ipaddress associated to eth0

 

 

 

best regards

 

tinku

 

 

QuoteReplyEditDelete

 

 

2008-07-24 02:05:36     Re: dual network interface issue

Mike Frysinger (UNITED STATES)

Message: 59303   

 

i said that is correct behavior

Attachments

    Outcomes