Redundancy & load balance by using static route

[acbennyma]

I have build a lab at home and try to test Redundancy and load balance by using static route.

I am trying to ping some internet IP from PC1, I find that it can perform Redundancy when I shutdown one of series ports of 2620 but load balance fail.

It is possible to do it ?

The Physical connection is as Below. 2620 two serial ports are connect to two 1720 series port

LanA(PC1 192.168.0.1) -> 2620->1720A & 1720B -> Hub(LanB) ->NAT Router(192.168.169.254) -> Internet

2620#sh ru

!

version 12.1

service timestamps debug uptime

!

memory-size iomem 10

ip subnet-zero

no ip finger

!

!

interface Ethernet0/0

ip address 192.168.0.254 255.255.255.0

!

interface Serial0/0

ip address 172.0.0.1 255.255.255.252

no fair-queue

clockrate 128000

!

interface Ethernet0/1

no ip address

shutdown

!

interface Serial0/1

ip address 172.0.0.6 255.255.255.252

clockrate 128000

!

ip classless

ip route 0.0.0.0 0.0.0.0 Serial0/1

ip route 0.0.0.0 0.0.0.0 Serial0/0

!

line con 0

1720B#sh ru

!

version 12.2

!

hostname RouterB

!

memory-size iomem 20

ip subnet-zero

!

interface FastEthernet0

ip address 192.168.169.51 255.255.255.0

ip nat outside

speed auto

!

interface Serial0

ip address 172.0.0.2 255.255.255.252

ip nat inside

no fair-queue

!

ip nat inside source list 1 interface FastEthernet0 overload

ip classless

ip route 0.0.0.0 0.0.0.0 192.168.169.254

ip route 192.168.0.0 255.255.255.0 192.168.169.50

ip route 192.168.0.0 255.255.255.0 172.0.0.1

no ip http server

!

access-list 1 permit 192.168.0.0 0.0.0.255

!

line con 0

1720A#sh ru

!

memory-size iomem 25

ip subnet-zero

!

!

interface FastEthernet0

ip address 192.168.169.50 255.255.255.0

ip nat outside

speed auto

!

interface Serial0

no ip address

shutdown

!

interface Serial1

ip address 172.0.0.5 255.255.255.252

ip nat inside

!

ip nat inside source list 1 interface FastEthernet0 overload

ip classless

ip route 0.0.0.0 0.0.0.0 192.168.169.254

ip route 192.168.0.0 255.255.255.0 172.0.0.6

ip route 192.168.0.0 255.255.255.0 192.168.169.51

no ip http server

!

access-list 1 permit 192.168.0.0 0.0.0.255

!

line con 0

[thisisshanky]

By default your interfaces on the 2620 serial interface will be doing per-destination load balancing. For every destination address one of the serial links will be used. Try pinging a different address in the internet and see if LB works.

[Kevin Dorrell]

This is normally doing per-session balancing rather than per-packet load balancing. I think you can provoke per-packet load balancing, at a price, by disabling CEF and ip route cache.

Kevin Dorrell

Luxembourg

[acbennyma]

Yes, I try to use two ping, it can perform LB,

so is it possible to perform per-packet LB ?

I haven't enable CEF and ip route cache

[Kevin Dorrell]

ip route cache is enabled by default. You have to do no ip route cache on the relevant interfaces to disable it.

Kevin Dorrell

Luxembourg

[acbennyma]

Thx ! kevin,

This time, I have disable ip route cache in the 2620Router and use one ping to obtain the result.

It seems not work because I expect there will be input and output traiffc on both two serial interface,but now the result seems no output rate on two serial interfaces.

Does my concept is right ? traffic which leave from router to interface can be seen as output rate ?

2620#sh int | i bits/sec

5 minute input rate 11000 bits/sec, 1 packets/sec

5 minute output rate 11000 bits/sec, 1 packets/sec

5 minute input rate 6000 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

5 minute input rate 5000 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

[Kevin Dorrell]

The concept is right. I don't know why it does not seem to be working ... I'll have to do some reading. I don't know how it arbitrates between the two routes when route cache is disabled. I'll post back to you if I find anything.

Kevin Dorrell

Luxembourg

[acbennyma]

Thank you very much !

kevin.