CISCO 3560 SVI Issue

[md.sakibnaz]

Hello all.

I am facing one issue with my CISCO 3560 Switch and need your help urgently.

I have a Sever, Switch 3560 and a Router. Where Router is conncted with Internet.

The Link connection is like:

PC --- (Access Vlan 10) ---> CISCO ---(Access Vlan 10) ---> Router ---> Internet

Config Details are:

• I used SVI on 3560. So Interface Vlan 10 having IP: 192.168.10.10/24 and Router Interface is 192.168.10.11/24.
• All the links are Access.
• I added one default-route on Switch with next-hop 192.168.10.11.
• The PC GW is 192.168.10.10.

The problem I am facing when from PC I am pinging google.com. It reports Redirect Network(New nexthop: 192.168.10.11) and making huge packet loss. But when PC GW is 192.168.10.11 then all are Ok. But I want to set the PC GW to the SVI IP (192.168.10.10).

As the 3560 having default-route towards next-hop 192.168.10.11, can you suggest why this redirect issue happening? And whats the solution?

Regards.

[ALIAOF_]

I'm assuming you setup an access port on the router and then same on the switch.  Switch is setup as Layer 2 with the "ip default-gateway 192.168.10.11" command?

In such a case you'll have to use the router as your gateway on the server.  If you want to accomplish what you are trying to accomplish you'll need to make some changes:

- Setup a sub interface on the router with an IP of 192.168.10.11/24

- Setup a trunk between the router and the switch

- Setup the switch in L3 mode and enable IP routing and then add "ip route 0.0.0.0 0.0.0.0 192.168.10.11" on the switch

- Now make the SVI IP 192.168.10.10 as your default gateway on the server.

[mahmoodmkl]

Hi,

U need to enable ip routing on u r 3560 and configure the default route to your router.

Thanks

[Raju Sekharan]

"Redirect Network(New nexthop: 192.168.10.11)" is an expected behavior. This is called ICMP redirect

You can read the below link to undersand ICMP redirect

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094702.shtml

Your PC points DG to switch and switch points to Router. Both are in same network. so when switch recevies packets destined to internet, it will send an ICMP redirect to PC telling, you can send it directly to router than sending to me and me sending to router

A better desgin would be to move the router to different subnet if you want the 3560 as L3 switch

If you don't need routing on 3560, use router as defaul-gateway of the PC

Thanks

Raju

[Raju Sekharan]

Hi

You can also disable icmp redirect by configuring " no ip redirects" on the VLAN interface of the switch

Thanks

Raju