redundancy of 2 core switches

[ONLYUNITED]

Hi,

im new to this. If i got 3 switches [3560], i need to use 1 as a layer 3 switch so that data vlan can communicate with voice vlan. however, if this core die, my whole network die. how can i have redundancy. Can i use another 3560 as the core also.

what special config is needed for 2 core switches.

many thanks.

[hitesharora]

Hi,

The best is if you configure all the three as Layer 3 switch and Layer2 trunk among three swicthes.

Rgds

[pciaccio]

You can apply IP addresses to all three switches and use HSRP. With HSRP you gateway to a virtual IP address that all three routers are advertising. If the active router fails then it will fall back to the standby router. Your traffic is not lost, the failover happens quickly. When the failed router is restored then you can have it become active again...

[ONLYUNITED]

Hi Pciaccio,

Thanks for your reply.

Apologies for my ignorance. So does the following config enable HSRP:

Switch#conf t

Switch (config)# int gi0/1

Switch (config-if)# standby 1 ip

Switch (config-if)# end

So I can use individual ip addresses for the 3 switches and all their default gateway is pointing to the virtual IP address. where am i going to set the virtual ip address and mac address

As this is an existing setup, the 3 new 3560 is replacing 3 old switches. Currently, the old switch is pointing to their Firewall as the default gateway where they can access internet and etc. So how shd i take into consideration the firewall if im using HSRP.

Many thanks.

[ONLYUNITED]

Hi Pciaccio,

Thanks for your reply.

Apologies for my ignorance. So does the following config enable HSRP:

Switch#conf t

Switch (config)# int gi0/1

Switch (config-if)# standby 1 ip

Switch (config-if)# end

So I can use individual ip addresses for the 3 switches and all their default gateway is pointing to the virtual IP address. where am i going to set the virtual ip address and mac address

As this is an existing setup, the 3 new 3560 is replacing 3 old switches. Currently, the old switch is pointing to their Firewall as the default gateway where they can access internet and etc. So how shd i take into consideration the firewall if im using HSRP.

Many thanks.

[abhishek_nandavat]

Hi,

Refer the following link for HSRP configuration-->

http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124cg/hiap_c/ch20/haiphsrp.htm

You can set an individual address for each router and then you make a standby group where you make failover router as the member of that group. And for group you assign another IP which acts as the virtual IP. You dont need to set the mac address.

While implementing HSRP, the default gateway still remains the firewall only. You can set that for the vlan.

Hope this helps...

Regards,

AbhisheK

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[albert.remo]

Hi!

Good Day! Having the 3 switches run layer 3 is a good option creating a partial mesh network. Connect a layer 2 trunk to this switches that creates somewhat a triangle. Put ip address on the VLAN interfaces and run a dynamic routing protocol if supported. Another option is to have redundant layer 3 switches to act as the core. HSRP is a good option but if you would need the benefits of HSRP plus load balancing (specially when running voice), GLBP (Gateway Load Balancing Protocol) is another option.

You can check on these links about GLBP:

Gateway Load Balancing Protocol

http://www.cisco.com/en/US/products/sw/iosswrel/ps1839/products_white_paper09186a00801541c8.shtml

Gateway Load Balancing Protocol Options

http://www.cisco.com/en/US/products/ps6600/products_data_sheet0900aecd803a546c.html

Hope these helps,

Regards,

Albert

[albert.remo]

Hi!

My apology, currently Cisco3560 has no support for GLBP thus you can only run HSRP.

Regards,

Albert