Testing the redundancy using VRRP

bjacob1976 · ‎09-28-2006

Hi All,

I am testing the redundancy using VRRP in a lab environment.I need your help in fixing this issue.This is really basic stuff,guess am missing some configs for the trunk between Switch-1 & Router-1,Switch-1 & Switch-3.Should I use native vlan?

Can anyone help me out to fix this issue?

Many Thanks in advance

Scenario:Attached.

Issue:I am not able to ping from 10.0.0.2 to 10.0.0.5 and vice-versa,All the interfaces are UP.

If I change the Switch1 to a hub,I can ping the IP addresses.

All switches are Cat6500 series switches with Native IOS.

Routers are Cisco7206

Configs given below:

----------------------

Router1

-------

interface FastEthernet4/0.200

encapsulation dot1Q 200

ip address 10.0.0.2 255.255.255.0

vrrp 4 timers learn

vrrp 4 ip 10.0.0.1

vrrp 4 priority 254

end

Switch1

--------

interface GigabitEthernet1/1

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 200

switchport mode trunk

no ip address

end

interface GigabitEthernet2/1

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 200

switchport mode trunk

no ip address

end

Switch3

-------

interface GigabitEthernet2/1.200

encapsulation dot1Q 200

ip address 10.0.0.5 255.255.255.0

vrrp 4 timers learn

vrrp 4 ip 10.0.0.4

vrrp 4 priority 254

end

interface GigabitEthernet1/1.300

encapsulation dot1Q 200

ip address 192.168.0.2 255.255.255.0

vrrp 4 timers learn

vrrp 4 ip 192.168.0.1

vrrp 4 priority 254

end

Router2

-------

interface FastEthernet4/0.200

encapsulation dot1Q 200

ip address 10.0.0.3 255.255.255.0

vrrp 4 timers learn

vrrp 4 ip 10.0.0.1

vrrp 4 priority 100

end

Switch2

--------

interface GigabitEthernet1/1

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 200

switchport mode trunk

no ip address

end

interface GigabitEthernet2/1

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 200

switchport mode trunk

no ip address

end

Switch4

-------

interface GigabitEthernet2/1.200

encapsulation dot1Q 200

ip address 10.0.0.6 255.255.255.0

vrrp 4 timers learn

vrrp 4 ip 10.0.0.4

vrrp 4 priority 100

end

interface GigabitEthernet1/1.300

encapsulation dot1Q 200

ip address 192.168.0.3 255.255.255.0

vrrp 4 timers learn

vrrp 4 ip 192.168.0.1

vrrp 4 priority 100

end

bjacob1976 · ‎10-01-2006

Hi All,

Can someone help me on this trunk configuration between Switch-1 to Router-1 and Switch-1 to Switch-3.

Thanks

hdecreis · ‎10-01-2006

Hello Jacob,

AFAICT your trunk configuration seems correct...

1/ What does "show int ..." and "show int ... switchport" returns on Switch1 for the trunking ports ?

2/ Reading your scenario, you need to pass only one VLAN between Router1 and Switch3, why bother with trunking then (unless you have other requirements not listed in your post) ? Anyway, does connectivity is OK when replacing trunk configuration with Access ports ?

Apart from the trunking problem, just a remark regarding the VRRP group numbers: I can see you are using same group number for different virtual routers on the same ethernet segment. As VRRP construct the virtual MAC address based on the group number, this is leading to duplicated MAC addresses. You should use different group numbers within the same broadcast domain / device.

Hope this helps

Cheers

bjacob1976 · ‎10-02-2006

Hi hdecreis

Thanks for your suggestions and time.

1.Show int and show int switchport is given below:

sh int gigabitEthernet 1/1

GigabitEthernet1/1 is up, line protocol is up (connected)

Hardware is C6k 1000Mb 802.3, address is 0018.7385.fe20 (bia 0018.7385.fe20)

MTU 1500 bytes, BW 100000 Kbit, DLY 10 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full-duplex, 100Mb/s

input flow-control is off, output flow-control is on

Clock mode is auto

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:18, output 00:00:06, output hang never

Last clearing of "show interface" counters 1w4d

Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

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

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

204109 packets input, 22389906 bytes, 0 no buffer

Received 124095 broadcasts (123996 multicasts)

0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog, 0 multicast, 0 pause input

0 input packets with dribble condition detected

53142 packets output, 13240412 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 babbles, 0 late collision, 0 deferred

0 lost carrier, 0 no carrier, 0 PAUSE output

0 output buffer failures, 0 output buffers swapped out

sh int switchport

Name: Gi1/1

Switchport: Enabled

Administrative Mode: trunk

Operational Mode: trunk

Administrative Trunking Encapsulation: dot1q

Operational Trunking Encapsulation: dot1q

Negotiation of Trunking: On

Access Mode VLAN: 1 (default)

Trunking Native Mode VLAN: 1 (default)

Voice VLAN: none

Administrative private-vlan host-association: none

Administrative private-vlan mapping: none

Administrative private-vlan trunk native VLAN: none

Administrative private-vlan trunk encapsulation: dot1q

Administrative private-vlan trunk normal VLANs: none

Administrative private-vlan trunk private VLANs: none

Operational private-vlan: none

Trunking VLANs Enabled: 200

Pruning VLANs Enabled: 2-1001

Capture Mode Disabled

Capture VLANs Allowed: ALL

Unknown unicast blocked: disabled

Unknown multicast blocked: disabled

2.You are right only single Vlan 200 is passed between Router1 and Switch3.

I have tried replacing the trunk with access ports,but no luck.

I can reach from switch1 to switch-5 but not to router1,the trunk between switch-1 & router-1 is creating the problem.

Router-1 is Cisco 7206VXR and I cannot set the command as "encapsulation dot1q native" because of the IOS version .Do you think adding this command will solve the problem? Any issues with native Vlan matching?

Once again thanks for your comment on VRRP group numbers,I will change it.

Thanks in Advance

bjacob1976 · ‎10-03-2006

Hi All,

Pl ignore this post.

Thanks