Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Routing Issue

Hello All:

I'm having an issue with my ISP and it looks to me like a routing issue their end. They assinged me a "static" ip which is really a 20 year DHCP leased IP.

Connected directly to their modem with my laptop I can pull the following configuration from their DHCP server

IP - 24.225.238.137

GW - 24.225.238.129

Subnet - 255.255.255.192

Can get out no problem. When I transfer these IP's to my Sonicwall (nat enabled). I cannot get out.

Looking out the routing tables on the firewall itself I see 2 discovered routes. 1 for my internal

and one for ISP. The internal is good, anything destined for 192.168.1.0 network, use GW 192.168.1.1

However, the route for ISP reads anything destined for 24.225.238.128, use GW 24.225.238.137.

I cannot understand why it's seing my static IP as the gateway? this would explain why when moving to the Firewall with this config, it can't get out. Is this a correct assumption. Wrong Gateway is what I see and why is the route looking for .128

Any insights would be appreciated.

2 REPLIES
Cisco Employee

Re: Routing Issue

It is normal for the FW to have an entry for 24.225.238.128/27 to 24.225.238.137. This just say that to reaqch any destination on that /27 use the directly connected subnet. Do have a default route pounting at 24.225.238.129 ? That seems to be what the problem is.

Hope this helps,

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México 
Paseo de la Reforma 222 Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
Bronze

Re: Routing Issue

Indeed -- it looks like the firewall isn't using the default route provided by DHCP. Hopefully this is configurable, otherwise you'll need to statically define a default gateway.

106
Views
0
Helpful
2
Replies