I have only learned GLBP on paper, this is the first time I configured it and tried out.

1841-1 shall be the active for vlan 10, 20 and 30.

1841-2 shall be the active for vlan 99, 100 and 101.

Vlan 99, 100 and 101 are user vlans, I have only configured the vlan 99.

1841-1 configuration for vlan 10

interface FastEthernet0/0.10
encapsulation dot1Q 10
ip address 172.16.10.1 255.255.255.0
glbp 10 ip 172.16.10.3
glbp 10 timers msec 500 msec 1500
glbp 10 priority 150
glbp 10 preempt
glbp 10 client-cache maximum 25
end

1841-1 configuration for vlan 20

interface FastEthernet0/0.20
encapsulation dot1Q 20
ip address 172.16.20.1 255.255.255.0
glbp 20 ip 172.16.20.3
glbp 20 timers msec 500 msec 1500
glbp 20 priority 150
glbp 20 preempt
glbp 20 client-cache maximum 25
end

1841-1 configuration for vlan 30

interface FastEthernet0/0.30
encapsulation dot1Q 30
ip address 172.16.30.1 255.255.255.0
glbp 30 ip 172.16.30.3
glbp 30 timers msec 500 msec 1500
glbp 30 priority 150
glbp 30 preempt
glbp 30 client-cache maximum 25
end

1841-1 configuration for native vlan 200

interface FastEthernet0/0.200
encapsulation dot1Q 200 native
ip address 192.168.200.1 255.255.255.0
end

1841-1 configuration for user vlan 99

interface FastEthernet0/0.99
encapsulation dot1Q 99
ip address 10.99.99.1 255.255.255.0
glbp 99 ip 10.99.99.3
glbp 99 timers msec 500 msec 1500
glbp 99 preempt delay minimum 60
glbp 99 weighting 100 lower 55 upper 90
glbp 99 client-cache maximum 254
glbp 99 name user-99
glbp 99 weighting track 99 decrement 50
end

1841-2 configuration for vlan 10

interface FastEthernet0/0.10
encapsulation dot1Q 10
ip address 172.16.10.2 255.255.255.0
glbp 10 ip 172.16.10.3
glbp 10 timers msec 500 msec 1500
glbp 10 preempt
glbp 10 client-cache maximum 25
end

1841-2 configuration for vlan 20

interface FastEthernet0/0.20
encapsulation dot1Q 20
ip address 172.16.20.2 255.255.255.0
glbp 20 ip 172.16.20.3
glbp 20 timers msec 500 msec 1500
glbp 20 preempt
glbp 20 client-cache maximum 25
end

1841-2 configuration for vlan 30

interface FastEthernet0/0.30
encapsulation dot1Q 30
ip address 172.16.30.2 255.255.255.0
glbp 30 ip 172.16.30.3
glbp 30 timers msec 500 msec 1500
glbp 30 preempt
glbp 30 client-cache maximum 25
end

1841-2 configuration for vlan 99

interface FastEthernet0/0.99
encapsulation dot1Q 99
ip address 10.99.99.2 255.255.255.0
glbp 99 ip 10.99.99.3
glbp 99 timers msec 500 msec 1500
glbp 99 priority 150
glbp 99 preempt
glbp 99 weighting 150 lower 90 upper 140
glbp 99 client-cache maximum 254
glbp 99 name user-99
glbp 99 weighting track 99 decrement 60
end

1841-2 native vlan 200

interface FastEthernet0/0.200
encapsulation dot1Q 200 native
ip address 192.168.200.2 255.255.255.0
end

Verification

1841-2#sh glbp brief
Interface   Grp  Fwd Pri State    Address         Active router   Standby router
Fa0/0.10    10   –   100 Standby  172.16.10.3     172.16.10.1     local
Fa0/0.10    10   1   –   Listen   0007.b400.0a01  172.16.10.1     –
Fa0/0.10    10   2   –   Active   0007.b400.0a02  local           –
Fa0/0.20    20   –   100 Standby  172.16.20.3     172.16.20.1     local
Fa0/0.20    20   1   –   Listen   0007.b400.1401  172.16.20.1     –
Fa0/0.20    20   2   –   Active   0007.b400.1402  local           –
Fa0/0.30    30   –   100 Standby  172.16.30.3     172.16.30.1     local
Fa0/0.30    30   1   –   Listen   0007.b400.1e01  172.16.30.1     –
Fa0/0.30    30   2   –   Active   0007.b400.1e02  local           –
Fa0/0.99    99   –   150 Active   10.99.99.3      local           10.99.99.1
Fa0/0.99    99   1   –   Listen   0007.b400.6301  10.99.99.1      –
Fa0/0.99    99   2   –   Active   0007.b400.6302  local           –
Fa0/0.100   100  –   150 Active   10.100.100.3    local           10.100.100.1
Fa0/0.100   100  1   –   Listen   0007.b400.6401  10.100.100.1    –
Fa0/0.100   100  2   –   Active   0007.b400.6402  local           –

1841-1#sh glbp brief
Interface   Grp  Fwd Pri State    Address         Active router   Standby router
Fa0/0.10    10   –   150 Active   172.16.10.3     local           172.16.10.2
Fa0/0.10    10   1   –   Active   0007.b400.0a01  local           –
Fa0/0.10    10   2   –   Listen   0007.b400.0a02  172.16.10.2     –
Fa0/0.20    20   –   150 Active   172.16.20.3     local           172.16.20.2
Fa0/0.20    20   1   –   Active   0007.b400.1401  local           –
Fa0/0.20    20   2   –   Listen   0007.b400.1402  172.16.20.2     –
Fa0/0.30    30   –   150 Active   172.16.30.3     local           172.16.30.2
Fa0/0.30    30   1   –   Active   0007.b400.1e01  local           –
Fa0/0.30    30   2   –   Listen   0007.b400.1e02  172.16.30.2     –
Fa0/0.99    99   –   100 Standby  10.99.99.3      10.99.99.2      local
Fa0/0.99    99   1   –   Active   0007.b400.6301  local           –
Fa0/0.99    99   2   –   Listen   0007.b400.6302  10.99.99.2      –
Fa0/0.100   100  –   100 Standby  10.100.100.3    10.100.100.2    local
Fa0/0.100   100  1   –   Active   0007.b400.6401  local           –
Fa0/0.100   100  2   –   Listen   0007.b400.6402  10.100.100.2    –

It would be better to put a third router, so that one AVG there’s two AVF, one AVF down the other AVF will take over, if a AVG down the other AVF will take over.