Bonded t1 frame-relay 3640 configuration help!

[jenn01]

I'm a new Cisco user and had a bonded T1 installed, but can't get anything to work. The provider supplied me with a configuration for an 1841, but I can't get that to work in my 3640. Here are my specifics:

Cisco 3640 Router with 2 WIC-1DSU T1 & 1FE-2W
128MB DRAM and 32MB FLASH
IOS Version 12.4(7a) - c3640-ik9o3s-mz.124-7a.bin

The configuration they gave me (IP changed for display):

<--snip-->
!
! before applying, please ``write erase'' ``reload''
!
! configuration starts here:
!
service password-encryption
enable secret [your password]
no ip http server
ip subnet-zero
ip cef
no ip domain lookup
!
ip name-server 1.2.3.4
ip name-server 5.6.7.8
!
hostname [your hostname]
!
controller T1 0/0/0
framing esf
linecode b8zs
!
! the following assumes a full 1.5M T1 ( 24 x 64k channels )
!
channel-group 1 timeslots 1-24
exit
!
controller T1 0/1/0
framing esf
linecode b8zs
!
! the following assumes a full 1.5M T1 ( 24 x 64k channels )
!
channel-group 1 timeslots 1-24
exit
!
policy-map fair
class class-default
fair-queue
exit
exit
!
interface Multilink1
ip address 1.2.5.6 255.255.255.252
service-policy output fair
load-interval 30
no cdp enable
ppp multilink
ppp multilink fragment disable
ppp multilink links maximum 4
ppp multilink links minimum 1
ppp multilink group 1
exit
!
interface FastEthernet0/0
description Client LAN
ip address 1.2.3.4 255.255.255.224
ip verify unicast reverse-path
no keepalive
no shut
exit
!
!
interface Serial0/0/0:1
no ip address
encapsulation frame-relay IETF
load-interval 30
frame-relay lmi-type ansi
exit
!
!
interface Serial0/0/0:1.16 point-to-point
frame-relay interface-dlci 16 ppp Virtual-Template1
exit
exit
!
interface Serial0/1/0:1
no ip address
encapsulation frame-relay IETF
load-interval 30
frame-relay lmi-type ansi
exit
!
interface Serial0/1/0:1.16 point-to-point
frame-relay interface-dlci 16 ppp Virtual-Template1
exit
exit
!
interface Virtual-Template1
ip address 1.2.5.6 255.255.255.252
ppp multilink
ppp multilink links maximum 4
ppp multilink links minimum 1
ppp multilink group 1
exit
!
!
ip classless
!
ip route 0.0.0.0 0.0.0.0 Multilink1
!
banner login ^
Unauthorized access prohibited.
^
!
access-list 10 permit 1.2.0.0 0.0.0.255
access-list 10 deny any
!
logging buffered
ntp server 4.5.6.7
!
line con 0
login
password [your password]
exit
!
line vty 0 4
login
password [your password]
transport input telnet
access-class 10 in
exit
!
exit
!
write me
<--snip-->

First of all, these are not supported:

controller T1 0/0/0
controller T1 0/1/0

So I can't even enter this (no controller command) so I had to leave out the entire controller part... And:

interface Serial0/0/0:1
interface Serial0/0/0:1.16 point-to-point
interface Serial0/1/0:1
interface Serial0/1/0:1.16 point-to-point

are not supported. What I had to do here was:

interface Serial0/0
interface Serial0/0.16 point-to-point
interface Serial0/1
interface Serial0/1.16 point-to-point

And it still doesn't work. It won't bring up the Multilink or Virtual Template.

What am I doing wrong? The router works just fine on a single T1 frame-relay.

Thanks,
Jen

 

[jneiberger]

Here's a guide on PPP over Frame Relay:

http://www.cisco.com/en/US/products/ps6350/products_configuration_guide_chapter09186a00804a4097.html

The only thing I spotted at first glance is that you don't have frame-relay traffic-shaping configured on your serial interfaces. I've never configured PPPoFR before so I don't know if that is truly mandatory or not, but the guide makes it sound mandatory.

 

[jenn01]

Thanks jneiberger,

Yes I've read that and I tried using traffic-shapping as well. In fact I even tried their sample configuration on that page and that didn't work either.

When I first realized I couldn't get it to work, I found this page in this forum:

http://www.tek-tips.com/viewthread.cfm?qid=1225832&page=1

I tried that too (changing to frame-relay of course), but that failed too. Here is another link at Cisco where I have tried to configure this thing:

http://www.cisco.com/en/US/products/ps6350/products_configuration_guide_chapter09186a00804a4097.html

The above is for IOS 12.4 which is what I have. I copied their sample line-by-line without success. Everything comes up but the multilink and Virtual Template.

I have verified both T1 lines are up and functioning. I tested this by configuring the 3640 as a single T1 and it can ping out and the outside can ping in and I was also able to telnet to it from another location. There's something else wrong, but for the life of me I can't figure it out. It's not like this is some kind of super complicated configuration or anything.

Thanks for your help,
Jen

 

[jneiberger]

I'm sure you've done this but I have to ask...have you had your provider verify that they have their config working? It's possible that they don't have their end configured correctly. I don't know about PPPoFR, but perhaps that might keep your virtual interfaces in a down state.

 

[jenn01]

Hi jneiberger,

You are soooooo 100% right! Yesterday when I started working on this and couldn't get things working, I called them to verify that things were up and running correctly. They confirmed everything on their end was right and the problem is on my end. I struggled with this until midnight last night and then started on it again at 6:00am this morning. Still, no matter what I did I couldn't get the Multilink to come up. Everything else would come up just fine.

So about an hour ago I called them and said "hey guys, something has to be wrong on your end.". Of course they couldn't believe that and me being the customer must not know what I'm talking about. They said they can not provide me with support for my router. I then said "OK, let's just say I have your router sitting in front of me and it doesn't work? How are you NOW going to support me". They agreed to run some test on each line. I had to configure an old Cisco 1620 and helped them test each line. And guess what? Those jerks NEVER setup the bonding!!!!!! They rebuilt the circuit, I reconfigured the 3640 with my initial configuration and everything came up like a champ. I just now did this and I'm now waiting for a call back so I can bitch at them like they've never heard a lady bitch in their life. I'm also going to demand a credit for the circuit down time.

I knew I couldn't be that way off. I've done my Cisco certification classes and have at least a basic understanding of it all. Too bad the training doesn't provide you with real situations and we never touched on bonded circuit configs so I thought it must be something I'm not doing. Now I can live with myself again and have a restful weekend.

I want to thank you again jneiberger for being so helpful. If we were working as a team on this we would have been up yesterday. I should never take their word and believe they had their end up correctly in the first place. That would have saved me a lot of time and grief.

Have a great one,
Jen

 

[jneiberger]

Well, that's what these sorts of forums are for, right? I'm glad you got it working.

To be fair, there are so many different types of bonding (MLPPP, PPPoFR, MLFR, ATM IMA, etc.) that it would get pretty confusing for beginners. There's a reason they leave that sort of stuff out of the certification classes. It's too advanced for the CCNA course and it doesn't really have much of a place in the current CCNP track.

Anyway, I'm glad it's up and running!

John

 

[jenn01]

I agree jneiberger. Just like all that time I spent in college learning things I've yet to use in the real world. hahahaha

Since it sounds like you have a better diagnostic approach than our supplier, I've got a question for you. I've been playing around with the bonded circuits and sure enough, when both up it screams and I'm able to upload and download just under 3Mbps. However, if I disconnect one of those lines, I see that 50% of the packets are lost on a ping and internet browsing is slower than my 1980's dialup modem. I was under the impression that Multilink Point-To-Point Protocol (MLPPP) has the advantage of providing redundancy in the event that one or more of the T1 links in the bundle experience error, test or failure conditions and the remaining link(s) will continue to pass traffic up to their aggregate capacity.

From my tests I can't see this is the case. Possibly if I were to reconfigure the router to use only one line then it would probably work. Or my guess is that if there is a problem, the provider will have to diable the bundle on their end, but my end will then continue to function normally on the good line. Any thoughts on that?

I love forums like this and meeting such a great bunch of people.

Later,
Jen

 

[jneiberger]

Again, I've never used PPPoFR so I can't speak about this from experience. However, my guess is that this depends on how you're taking your interface down, and it also depends on how your network provider reacts to that outage. It could be that the far end doesn't see the PVC go down. If it doesn't know that the PVC is down, it doesn't know to remove that circuit from the multilink group. Therefore, return traffic back to your network alternates between a path that work and a path that doesn't work.

Were you actually pulling the circuit cable or were you just shutting down the interface or subinterface? Did you wait long enough for LMI keepalives to time out? That can take up to a minute. If you're still seeing 50% packet loss after a minute than I would be that the other side doesn't see the outage. If that's the case then you might be able to configure FREEK, frame relay end-to-end keepalives. I don't know how that would work with PPPoFR, though. Try it at your own risk. I think your service provider would have to participate in it for it to work.

 

[jenn01]

I found the problem. Following Cisco's advice (and as you found at Cisco), I entered the frame-relay traffic-shapping in the config. That will mess things up. After I removed this from the config upload/download with both T1's up were about 3Mbps. When I disconnected one, download was at half 1.5Mbps and no packets lost on ping. Just to see if this was some kind of fluke, I put the traffic-shaping back in and sure enough, things screwed up. It seems traffic-shaping will send packets via round-robin and ignore the bonded circut. Just goes to show you that you can't rely on what you read.

Gone for the weekend,
Jen