Layer 3 port-channel with HSRP

[noobieee7]

Hi,

I have the below setup.

cisco 3550-1 ---- layer 3 etherchannel --- cisco 3550-2

                                                                |

                                                                | layer 2 etherchannel

                   ---- layer 3 etherchannel --- cisco 3550-3

The cisco 3550-1 is connected via 2 physical port to 3550-2 and via another 2 physical port to 3550-3. Between 3550-2 and 3550-3 is connected with a layer 2 etherchannel.

May I know how can I setup HSRP on the 3550-2 and 3550-3, which will connect to the 3550-1? The aim is to have layer 3 point to point between 3550-2 to 3550-1 and 3550-3 to 3550-1 with HSRP configuration.

[Jon Marshall]

noobieee7 wrote:
Hi,
I have the below setup.
cisco 3550-1 ---- layer 3 etherchannel --- cisco 3550-2
                                                                |
                                                                | layer 2 etherchannel
                   ---- layer 3 etherchannel --- cisco 3550-3
The cisco 3550-1 is connected via 2 physical port to 3550-2 and via another 2 physical port to 3550-3. Between 3550-2 and 3550-3 is connected with a layer 2 etherchannel.
May I know how can I setup HSRP on the 3550-2 and 3550-3, which will connect to the 3550-1? The aim is to have layer 3 point to point between 3550-2 to 3550-1 and 3550-3 to 3550-1 with HSRP configuration.

Assuming your vlans are being routed on the 3550-2 and 3550-3 for each vlan you would -

3550-2

int vlan 10

ip address 192.168.5.2 255.255.255.0

standby 10 ip 192.168.5.1

standby 10 priority 110

standby 10 preempt

standby 10 auth

int vlan 11

ip address 192.168.6.2 255.255.255.0

standby 10 ip 192.168.6.1

standby 10 priority 110

standby 10 preempt

standby 10 auth

3550-3

int vlan 10

ip address 192.168.5.3 255.255.255.0

standby 10 ip 192.168.5.1

standby 10 auth

int vlan 11

ip address 192.168.6.3 255.255.255.0

standby 10 ip 192.168.6.1

standby 10 auth

this would make 3550-2 the HSRP active for both vlans as the default priority is 100 and we have set 3550-2 HSRP to have priority of 110.

Jon

[noobieee7]

Hi Jon,

How about on the 3550-1? The connection to 3550-2 from 3550-1 and 3550-3 from 35501 are both aggregated from 2 physical link into 1 logical link

[Jon Marshall]

noobieee7 wrote:
Hi Jon,
How about on the 3550-1? The connection to 3550-2 from 3550-1 and 3550-3 from 35501 are both aggregated from 2 physical link into 1 logical link

Not sure what you mean. The connections between 3550-1 and the other 2 switches are L3 etherchannels so you would simply route from 3550-2/3 to 3550-1.

Jon

[Ganesh Hariharan]

Hi Jon,
How
about on the 3550-1? The connection to 3550-2 from 3550-1 and 3550-3
from 35501 are both aggregated from 2 physical link into 1 logical link

What i understand with the topology your 3550-1 switch is connected with 2550-2 and 3550-3 switch via L2-L3 etherchannel combination and you want to have HSRP between 3550-2 and 3550-3 for users coming from 3550-1 switches,If yes then create L3 etherchannel with assiging ip to portchannel interface and cofnigure HSRP in portchannel inetrface with point a default route in 3550-1 switch towards the vip of the HSRP.

Check out the below link for more information

http://www.cisco.com/en/US/docs/switches/lan/catalyst3550/software/release/12.1_12c_ea1/configuration/guide/swethchl.html#wpxref12748

Hope to Help !!

Ganesh.H

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[ramji_avinash]

Dear Ganesh,

Y should we conf a default route pointing towards the VIP in the 3550-1 switch ,y i am asking is any how in the 3550-2 and 3550-3 u ll have a default route configured towards the internet ?if it has to go to the lan it will be done by searching the CAM table in the 3550-1 switch itself ,but if it has to go the remote destination it will search for the GATEWAY which will the VIP configured on the 3500-2 and 3550-3 switches , if the default route is not configured on the 3550-2 and 3550-3 switches it will reply as destination host not reachable ? pls clarify i am confused!!!

[Ganesh Hariharan]

Dear Ganesh,
Y should we
conf a default route pointing towards the VIP in the 3550-1 switch ,y i
am asking is any how in the 3550-2 and 3550-3 u ll have a default route
configured towards the internet ?if it has to go to the lan it will be
done by searching the CAM table in the 3550-1 switch itself ,but if it
has to go the remote destination it will search for the GATEWAY which
will the VIP configured on the 3500-2 and 3550-3 switches , if the
default route is not configured on the 3550-2 and 3550-3 switches it
will reply as destination host not reachable ? pls clarify i am
confused!!!

Hi Ramji,

The network route used by a router/switch when no other known route exists for a given IP packet's destination address it uses a default route in the routing table,so If a lan user needs to access the internet which is connected in 3550-1 then traffic lands in 3550-1 and from there 3550-1 it will send to vip ip address configured in uplink switches for redundancy purpose.

Hope to help !!

Ganesh.H