Routing prob. Home lab
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Hi all, *loving* the shows and learning a ton (or so I thought)
Here's the LAN design.
Cable modem >> dd-wrt router/AP (192.168.1.0 int lan) >> cisco 2960 switch >> Cisco 2851 router(DHCP .1.3 IP Gi0/0) >> (192.168.3.0 int lan Gi0/1) cisco 3750 >> linux laptop (static .3.50 IP).
Here's my symptom:
The laptop can ping the 192.168.1.0 network fine.
It can ping my public IP from the cable thieves.
If I ping yahoo.com or 8.8.8.8 (my typical targets), It will resolve the yahoo IP, but stop there.
traceroute ends at my dd-wrt router.
nslookup works too.
What am I missing? Being able to resolve a domain name but no results from a ping (or web request) is tossing me for a loop.
I also tried DMZ'ing the 2851.
TIA,
Dave -
What is your Default Gateway set to?
What is your DNS settings set to?
what is the ip address and subnet of your internal network? -
David,
It could be a number of things, but my best guess would be a bad NAT configuration on the DD-WRT router. Most likely, the DD-WRT box is configured to NAT hosts with a source IP of 192.168.1.0/24. You Linux box is in the 192.168.3.0/24 subnet so it doesn't match the NAT rule. The DNS lookups are most likely working because DD-WRT uses DNS Masq by default so the lookups actually happen against that box. I could be completely wrong, but that is my first thought.
If that is correct, then there are two possible solutions:- Update the NAT rule on the DD-WRT box to include 192.168.1.0/24 and 192.168.3.0/24.
- Configure NAT on the Cisco router to hide the 192.168.3.0/24 network from the DD-WRT box.
Option #2 would result in double-NAT which is not the greatest thing in the world, so I would go with #1 if I were you.
If that isn't the case, we can do some more digging, but that scenario definitely fits the problem you are describing.
Thanks for watching,
Don Pezet
Host, ITProTV