2611XM gets WAN IP from cable modem but internet doesnt work

[GM Singh]

Hi,

I am having a strange problem with my 2611XM router. At my home I am have put my cable modem in bridge mode and trying to configure internet access through Cisco 2611XM router. Here is bit detail about configuration

interface FastEthernet0/0

 description WAN
 ip address dhcp
 ip nat outside
 ip virtual-reassembly
 ip route-cache flow
 duplex auto
 speed auto
!
interface FastEthernet0/1
 description LAN
 ip address 192.168.99.1 255.255.255.0
 ip nat inside
 ip virtual-reassembly
 duplex auto
 speed auto
 no mop enabled
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 FastEthernet0/0
!
!
ip http server
ip http authentication local
ip http secure-server

ip nat inside source route-map SDM_RMAP_1 interface FastEthernet0/0 overload

!
access-list 101 permit ip 192.168.99.0 0.0.0.255 any
!
route-map SDM_RMAP_1 permit 1
 match ip address 101
!
!
!
control-plane
!
!
!
!
!
!
!
!
!
!
line con 0
line aux 0
line vty 0 4
 privilege level 15
 password XXX
 login local
 transport input telnet ssh
!
ntp clock-period 17208167
!
end

The issue is internet is not accessible from 192.168.99.0 network. I cant even ping any public ip from router. Though I am successfully getting WAN ip on interface fa0/0 from cable modem. Any help be appreciated.

Thanks

[Terence Payet]

Hi,

I presume you're getting a public ip address from your provider.

Can you check if you are getting the correct gateway by doing sh ip route.

The default route should point towards the ISP. If the route is there, try and ping the gateway to make sure it is reachable from your router.

HTH.

Regards,

Terence

[GM Singh]

Thanks for reply Terence. Default route was the issue,  And it was fixed by changing fa0/0 to dhcp in ip route command.

[johnlloyd_13 · Accepted solution]

hi,

try below:

no ip route 0.0.0.0 0.0.0.0 FastEthernet0/0
no ip nat inside source route-map SDM_RMAP_1 interface FastEthernet0/0 overload
no access-list 101 permit ip 192.168.99.0 0.0.0.255 any

ip route 0.0.0.0 0.0.0.0 dhcp
access-list 1 permit 192.168.99.0 0.0.0.255
ip nat inside source list 1 interface FastEthernet0/0 overload

[GM Singh]

Hi John

Thank you so much for solution. Although I have changed all three lines as you recommended but The only change which was needed was to change

ip route 0.0.0.0 0.0.0.0 FastEthernet0/0

to

ip route 0.0.0.0 0.0.0.0 dhcp

Now that internet is working. I was doing speed test and getting test results as 21M Down/10M Up. I have 100M Down / 10M Up connection. My question is whether something need to be streamlined in router configuration or 2611XM has only that much throughput as I have gotten in Speedtest. My though was that because I have fastethernet ports on router I will get speedtest result near about 80M Down and 10 M up. Any thoughts?

[johnlloyd_13]

hi,

i don't think a 2611xm will push its throughput to 100 meg down.it's just for a home lab right?

are you sure about your cable modem speed as those are already for fiber (FTTH)?

try to play around with the FE speed/duplex settings and use FTP or iperf tests instead.

[GM Singh]

I have put ISR4000 series router at home lab just for testing and got 95M down and 9.5M Up. So that means 2611XM only have 20M throughput. Thanks

[GM Singh]

Hi John

With this setup at homelab I got internet working and everything seem to working until I sent ICMP4 ping to my pc which is directly connected with fa0/1 on 2611XM router. But it times out. But I can ping fa0/1(192.168.99.1) from my PC. I scratched my head quite a bit but didn't work. Any idea?