Default Gateway issues

Mar 24, 2005 6 Replies
A

Hi, I have a problem. I have configured a Cisco 2600 to do DHCP and currently I am testing in a lab enviornment. I have two laptops hooked up to a netgear 4port hub which is connected to the 2600 ethernet port. Both Laptops are set to obtain ip address from dhcp server. Both laptops do get ip address however no default gateway. Pinging to the router from both laptops works. However when I try to ping from one laptop to the other. I cannot do this. Both latops are on the same subnet. Is this issue because of the default gateway not being in the ipconfig or is there a problem with cisco doing dhcp?



Thanks in advance for all your responses and help



Asif



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M

Hi, if I understand you right, both laptops are in the same subnet and are connected to the same HUB (repeater)? If so than please check your laptop's firewall. Out-of-the Box XP might disallow incoming ICMP The default-gateway is used ONLY when the destination IP is OUTSIDE the local subnet-range.

Mathias

snipped-for-privacy@gbc.com schrieb:

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A

Hi, Thanks for responding. These two laptops are running Win2K OS. Both get Ip addresses and both laptops can ping the router. but they cannot ping each other. (request timed out error ) Where would I check the laptops firewall ?

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A

Hi thanks for responding so quick.Both laptops are running WIN2K OS. what do you mean by laptops firewall?

Thanks

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A

I guess I found the problem. I had to add default-router command under ip dhcp pool name with this entry now I am able to see the default gateway under ipconfig. However I am still not able to ping from either Laptops which are running WIN2K.

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A

Make sure the subnet masks on the laptops are the same. Also, make sure you're using straight thru cables from the router and laptops to the switch. Is the interface on the router up? (no shutdown)?

As long as the interfaces are up, firewalls on laptops disabled, and subnet masks correct, you should be able to ping any device on the subnet.

-aun.

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B

You can't ping the other laptop from either laptop? Run ethereal

formatting link
you'll also need to install winpcap) on one of the laptops so you can see the network traffic. This should help you troubleshoot. Look to make sure arp is working properly if so then see if the pings are making it on to the wire if so then my experience says

99% of the time it's a host-based firewall problem (ie. zone alarm, norton security, mcafee, etc). If you're not running a host-based firewall then something is wrong with IP or ICMP.

Once I had a problem that was fixed by removing TCP/IP under the Windows 2000 network configuration for that network connection, rebooting and then reinstalling it.

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