[Beowulf] How to judge whether an ip address is local or not

Gerry Creager gerry.creager at tamu.edu
Mon Aug 15 13:26:23 PDT 2005


Mark Hahn wrote:
>>>	 I need to judge whether an ip address is local in kernel state.
>>>	 Can anyone help me?
>>>	 Great appreciation to any apply.
>>
>>What do you mean by "local"?  There are all sorts of ways to learn all
>>sorts of pieces of information about ip addresses and network
> 
> 
> I thought the query was really "how can I tell if an IP is local,
> xor if it requires going through a router".  I have no idea what 
> the reference to "kernel state" means - obviously the kernel uses 
> the same sequence of increasingly specific routes to determine how 
> to handle a packet.  the routes are not privileged (/sbin/ip route show 
> works fine as a normal user)

I hope this doesn't add to the confusion already here; I, too, don't 
understand the reference to 'local in kernel state'.  Are you 
specifically referring to 127.0.0.0/8?

Otherwise, if the bridging table resolves the MAC address and doesn't 
resort to sending a responding packet to the routing table for 
resolution, it's local.

Gerry
-- 
Gerry Creager -- gerry.creager at tamu.edu
Texas Mesonet -- AATLT, Texas A&M University	
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