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Network–Ping/No Ping

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I have a particular IP address on a subnet, let’s say, 198.200.234.30 and I can ping this address from another subnet from all IP addresses but one particular IP, 198.200.235.230. There are no ACL’s in the router. When I trace route, the path stops at the 198.200.234.30 gateway, but all IP’s in that subnet can be reached. Any ideas?

Thanks,
skywalker

Topic

Clarifications

In reply to Network–Ping/No Ping

Clarifications

Two possibilities

In reply to Network–Ping/No Ping

Understand that there is not a lot of information in your posting, so i am assuming some things.

What i think can do this is that you have an IP address conflict, which means the IP is on two devices on the network.

The default gateway has two different routes to reach the IP address and the wrong one has is the primary route.

I would need more information on your set up, how you conduct your tests and such to give you a better idea of what can be happening.

More info

In reply to Two possibilities

I have an Avaya PBX, 1.30 and a server that pulls data from the PBX, 2.230. 2.230 can ping any other IP on the 1.0 network, except 1.30. 1.30 can be pinged by any other IP on the 2.0 network. I can run a tracert from 2.230 to 1.30 and it hangs up at the gateway, any other IP from 2.0 network traces all the way to the 1.30 address.

Any other info you would like, just let me know.

skywalker

Update

In reply to More info

Any ideas?

subnet mask

In reply to More info

Can you tell me the subnet masks of your server and PBX?

mask?

In reply to Network–Ping/No Ping

humm so your question is: you have 1 subnet 192.200.234.XX/? and from host 192.200.234.30/? you can ping all hosts on subnet 192.200.235.XX/? except host 192.200.235.30/? how come?

As the other poster said, need more information. the actual address is only 1 part of the total address. If the subnet mask on the host 192.200.235.30 is not the same as all other hosts on that subnet, that could be the problem.

Info

In reply to mask?

IP info: PBX 198.200.234.30 Mask /24
IP info: PC 198.200.235.230 Mask /22

All IP’s on 235.0/22 can ping PBX, only 235.230/22 cannot.

235.230/22 can ping all IP’s on 234.0/24 no problem.

skywalker

Your masks are wrong

In reply to Info

198.200.235.0 /22 has a network of
198.200.232.0 and a broadcast of
198.200.235.255.

Your 198.200.234.30 is within your network of 198.200.235.230 yet you set is as if it’s not.

When your 235.230 asks for the IP of 234.30, it expect it to be on the same network, so it asks for the ARP request directly instead of going to its default gateway.

I doubt very much that the other 234 are at /24, because if they are, none of the 235 should see it.

Info

In reply to Your masks are wrong

I just used those IP’s for informational purposes as to not use our IP scheme. Both IP’s that I am having trouble with are usable and in the proper ranges. That is what is so confusing about it.

skywalker

Network–Ping/No Ping

In reply to Network–Ping/No Ping

apply the gateway ip address or next hope
IP address to your defualt route instead of the port, you will see a drop on the CPU cycles as well.

[Author]

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