cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Announcements

Cisco Community Designated VIP Class of 2020

1263
Views
0
Helpful
3
Replies
Highlighted
Beginner

Cisco 1801 ATM -> Ethernet bridge issue

I recently purchased a UC520W for use at home to replace an 877W, would  like it to do all the front-end stuff, NAT, firewall, PPPoE, voice. Have  installed a 1801 in front of it to bridge ADSL to Ethernet (almost),  but having some issues.

1801 config:

-----------

no ip routing

!

interface ATM0

description OUTSIDE

no ip address

no ip route-cache

no atm ilmi-keepalive

pvc 8/3

  vc-hold-queue 1024

  encapsulation aal5snap

  exit

bridge-group 1

no shut

exit

!

interface FastEthernet0

description INSIDE

no ip address

no ip route-cache

speed 100

full-duplex

bridge-group 1

no shut

exit

!

bridge 1 protocol ieee

The UC520W is doing the PPPoE negotiation fine, so the 1801 is bridging  (I've tried an 877W as well), I can ping out from the UC520 and attached  PCs OK as well. But when it comes to email and web surfing....no joy.  Replacing the 1801 with a dumb domestic modem/router in bridge mode works without  issue.

Have tried bridge irb (both enabled/disabled) and also ip routing (both enabled/disabled), no change.

Why am I getting only a partial connection? Any thoughts welcome....and  just using the domestic modem/router is the ultimate fall back solution, but I'd like  to work out where its failing if I can.

Everyone's tags (4)
1 ACCEPTED SOLUTION

Accepted Solutions
Participant

Cisco 1801 ATM -> Ethernet bridge issue

Please, check you MTU in all the links. I think the problem could be the MTU in some interface.

Regards.

View solution in original post

3 REPLIES 3
Participant

Cisco 1801 ATM -> Ethernet bridge issue

Please, check you MTU in all the links. I think the problem could be the MTU in some interface.

Regards.

View solution in original post

Beginner

Re: Cisco 1801 ATM -> Ethernet bridge issue

Looks to have been an MTU problem (which was on my to-do list [but forgotten]), configured for 1452 on both the ATM and FastEthernet interfaces on the 1801 and FastEthernet on the UC520, all OK for the past 24 hours.

Thanks for the assist!

Hall of Fame Master

Re: Cisco 1801 ATM -> Ethernet bridge issue

You will have better results by using a cheap modem like the default ISP one, as bridge.

CreatePlease to create content
Content for Community-Ad
FusionCharts will render here