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New Member

load balancing between serial line and ISDN BRI

We are using ISDN BRI to backup and load balance a 128kbps leased line. However, no traffic flow on the ISDN channel.

Below are the show ip route, show ip cef and show interface:

BG1#sh ip cef 172.17.0.0 int

172.17.0.0/16, version 155, epoch 0, per-packet sharing

0 packets, 0 bytes

via 172.24.7.12, BRI0/0, 0 dependencies

traffic share 1, current path

next hop 172.24.7.12, BRI0/0

valid punt adjacency

via 10.62.1.30, Serial0/0, 0 dependencies

traffic share 1

next hop 10.62.1.30, Serial0/0

valid adjacency

0 packets, 0 bytes switched through the prefix

tmstats: external 0 packets, 0 bytes

internal 0 packets, 0 bytes

Load distribution: 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 (refcount 1)

Hash OK Interface Address Packets

1 Y special UNKNOWN 0

2 Y Serial0/0 point2point 0

3 Y special UNKNOWN 0

4 Y Serial0/0 point2point 0

5 Y special UNKNOWN 0

6 Y Serial0/0 point2point 0

7 Y special UNKNOWN 0

8 Y Serial0/0 point2point 0

9 Y special UNKNOWN 0

10 Y Serial0/0 point2point 0

11 Y special UNKNOWN 0

12 Y Serial0/0 point2point 0

13 Y special UNKNOWN 0

14 Y Serial0/0 point2point 0

15 Y special UNKNOWN 0

16 Y Serial0/0 point2point 0

refcount 6

BG1#sh ip ro 172.17.0.0

Routing entry for 172.17.0.0/16

Known via "eigrp 1", distance 90, metric 20537600, type internal

Redistributing via eigrp 1

Last update from 172.24.7.12 on BRI0/0, 00:02:20 ago

Routing Descriptor Blocks:

172.24.7.12, from 172.24.7.12, 00:02:20 ago, via BRI0/0

Route metric is 20537600, traffic share count is 1

Total delay is 21000 microseconds, minimum bandwidth is 128 Kbit

Reliability 255/255, minimum MTU 1500 bytes

Loading 3/255, Hops 1

* 10.62.1.30, from 10.62.1.30, 00:02:20 ago, via Serial0/0

Route metric is 20537600, traffic share count is 1

Total delay is 21000 microseconds, minimum bandwidth is 128 Kbit

Reliability 243/255, minimum MTU 1500 bytes

Loading 5/255, Hops 1

4 REPLIES

Re: load balancing between serial line and ISDN BRI

HI

I cannot see any backup n load commands under u r serial interface

If u want to have backup n load balance u need to configure it by using backup n load commonads in u r serial interface.

The config should be

config#int s0

config-if#backup int bri0

config-if#backup delay time in seconds

config-if#backup load 1-255

might be wrong but just got an idea.

Hope this helps

New Member

Re: load balancing between serial line and ISDN BRI

hi,

The backup commands have been configured, and the ISDN channels are up. The problem is no traffic flow on the ISDN channels even i can see the route is correctly point to the serial and ISDN interfaces. If i disable cef and fast switching on both the interfaces, and then disable fast switching on the f0/0, then there will be some traffic flow via the ISDN channels (about 25% of the total load). Can someone explain this behavior?

Bronze

Re: load balancing between serial line and ISDN BRI

Hello,

can you post the full configuration of your router ? Usually when you configure the backup interface command, the interface will be up but spoofing, and traffic will onll flow over that interface when the main interface goes down...

Regards,

Nethelper

New Member

Re: load balancing between serial line and ISDN BRI

interface Serial0/0

description 2Mbps Leased Line to Bangi (TMB)

bandwidth 128

ip address 10.62.1.30 255.255.255.252

no ip proxy-arp

ip load-sharing per-packet

backup delay 5 30

backup interface BRI0/0

backup load 30 10

load-interval 30

clockrate 128000

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