Routing if your own ip address the default gateway in windows xp?
Category: Computers > Internet
Asked by: vikky999-ga
List Price: $9.50
17 Oct 2006 23:01 PDT
Expires: 16 Nov 2006 22:01 PST
Question ID: 774585
Routing if your own ip address the default gateway in windows xp? Hi I have two laptops running windows XP A & B which can ping each other just fine if i assign them the following ip addresses. They are connected via crossover cable. A: 192.168.0.1 Subnet: 255.255.255.0 B: 192.168.0.2 Subnet 255.255.255.0 However If i change the ip & subnet of B to B: 192.168.1.2 Subnet: 255.255.0.0 Ping from A ----> B gives an expected and immediate Desination host unreachable Ping from B ----> A gives me a Request Timed out since B succesfully sends the ping to A but A cannot route the pong back to B Now here is the weird part ... If I add the ip of A as the default gateway for A now B can ping A successfully and A can now route the pong back to B. WHY WHY WHY ?? Since all packets sent by A to A's ip address are sent back via loopback , I dont understand why adding it as a default gateway should allow the pong to reach the wire ?? Additional Details 56 minutes ago Im not asking how to fix this problem but putting them in the same subnet. I realise they are in different subnets where one is subnet is a subset of the other. My question is why does adding the default gateway as "itself" allow the smaller subnet to be able to route packets to the larger subnet. Since all packets sent to itself are sent to loopback and never should show up on the wire. I dont know if this behaviour is OS specific..im running windows XP on both machines
|There is no answer at this time.|
Re: Routing if your own ip address the default gateway in windows xp?
From: c0r3dump-ga on 18 Oct 2006 04:29 PDT
Because of the ARP Protocol, When A (as gateway) recives a packet for B from A (himself, loopback) looks in his ARP table for the address of B, if it isn`t in the ARP table, ask everyone in the net sending a packet ARP request. For more information look at RFC 826
If you feel that you have found inappropriate content, please let us know by emailing us at firstname.lastname@example.org with the question ID listed above. Thank you.
|Search Google Answers for|