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. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

no access to internet on cisco 2801

The business that I am consulting for just got Charter Business Class internet (80M vs. 6M supplied by AT&T). Charter provide their SMC MIR (managed internet router)<---Meaning I cant change any settings in the modem. The company has a block of 5 static ips. 71.85.77.192/29. They told me that 71.85.77.193 was my gateway and  the usable were .194-.198, but this is also not true...After 2 tech calls I finally was told .193 is the gateway for the modem and .194 was for the router portion of the modem/router combo. So, the usable is only .195-.198. That all was just background information.

The physical setup is CHARTER -- CISCO 2801 Router -- CISCO 2950 Switch

So far I have 4 Vlans (not including Vlan 1) setup on the 2950 (Vlan 5, 6, 7, 8). It is trunked from G0/1 on the 2950 to Fa0/1 on the 2801. I am using subinterfaces on the 2801 for all the Vlans (and before you ask, all the encapsulations are there and I can ping from a device on each Vlan to its default gateway on the router). Vlan 8 is the server vlan (10.0.0.0/24). The server is acting a dhcp server for Vlan 5 (192.168.10.0/24) and 6 (192.168.11.0/24). The actual IP address of the server is 10.0.0.3. All of the subinterfaces of the router is x.x.x.1

I have 71.85.77.196 set on Fa0/0 on the router and it is set as ip nat outside. I have all of the other subinterfaces on Fa0/1 set to ip nat inside. I am using static and dynamic nat. I have the server ip address 10.0.0.3 nat'ed to 71.85.77.195 going out and the other way around coming in. I have an access list for the the dynamic nat for the other vlans going out.

I have the default gateway set at 71.85.77.193.

I have a static route set to exit on Fa0/0

I have the dns servers set on the router and i have issued the ip domain-lookup.

From the server I can ping 71.85.77.193 and see the correct nat translation on the router but the ping fails.

I can ping 71.85.77.193 from the router and it succeeds.

BUT I CANNOT PING ANYTHING ON THE INTERNET FROM THE ROUTER. My server says I have internet access, but I cannot browse to any website.

 

I am literally about to pull my friggin' hair out. I am running out of time on this project, and Charter seems to believe it is a problem with my equipment. I have literally reset the router and ONLY set the static ip on the router and still cannot browse....One note though...I can plug a laptop in on any of the ports on the charter router and set a static ip and I can instantly browse the internet.

 

What am I missing/what am I doing wrong? HELP! :(

Everyone's tags (3)
1 ACCEPTED SOLUTION

Accepted Solutions

Post your running config and

Post your running config and you will get better help. From your description I would remove the static route to Fa0/0 and set it as the ISP IP instead. I have seen some instances where setting to the interface provides quirky behavior. Are you sure you put outside interface overload? Sounds like it's getting to the outside interface and dying from a NAT configuration. I will attach a config from a working router maybe that will help:

interface GigabitEthernet0/0.2
 encapsulation dot1Q 2
 ip address 192.168.1.2 255.255.255.0
 ip nat inside
 ip virtual-reassembly in

interface GigabitEthernet0/0.14
 description (Inside Private Interface)
 encapsulation dot1Q 14
 ip address 192.168.14.1 255.255.255.0
 ip nat inside
 ip virtual-reassembly in

interface GigabitEthernet0/1
 ip address dhcp
 ip nat outside
 ip virtual-reassembly in
 duplex auto
 speed auto
 no cdp enable

ip nat inside source list NAT interface GigabitEthernet0/1 overload
!
ip access-list standard NAT
 permit 192.168.1.0 0.0.0.255
 permit 177.1.10.0 0.0.0.255
 permit 177.1.20.0 0.0.0.255
 permit 10.254.254.0 0.0.0.255

2 REPLIES

Post your running config and

Post your running config and you will get better help. From your description I would remove the static route to Fa0/0 and set it as the ISP IP instead. I have seen some instances where setting to the interface provides quirky behavior. Are you sure you put outside interface overload? Sounds like it's getting to the outside interface and dying from a NAT configuration. I will attach a config from a working router maybe that will help:

interface GigabitEthernet0/0.2
 encapsulation dot1Q 2
 ip address 192.168.1.2 255.255.255.0
 ip nat inside
 ip virtual-reassembly in

interface GigabitEthernet0/0.14
 description (Inside Private Interface)
 encapsulation dot1Q 14
 ip address 192.168.14.1 255.255.255.0
 ip nat inside
 ip virtual-reassembly in

interface GigabitEthernet0/1
 ip address dhcp
 ip nat outside
 ip virtual-reassembly in
 duplex auto
 speed auto
 no cdp enable

ip nat inside source list NAT interface GigabitEthernet0/1 overload
!
ip access-list standard NAT
 permit 192.168.1.0 0.0.0.255
 permit 177.1.10.0 0.0.0.255
 permit 177.1.20.0 0.0.0.255
 permit 10.254.254.0 0.0.0.255

New Member

michaelthanks for your reply

michael

thanks for your reply and the suggestion!

I will try setting the route to the ISP IP tomorrow as well as post the config for the router and the switch...should have done that when I posted...but I wasn't at the site.

Yes the dynamic nat for vlans 5,6 & 7 are overloaded on the outside interface like the config you have shown and the networks for those vlans are in the access-list with the correct wildcard mask...I think ;)

Vlan 8 has 1 server in it (for now) and I have static nat set for it, both going out and coming in...

once again thanks for your insight.

 

144
Views
0
Helpful
2
Replies