Re: Access port connection - Page 2

gurkamal01 · ‎02-12-2010

Hello,

This is collapsed core design.

I have 3550 which has a Gig access link connection to core switch 2(6513) on vlan253.

It also has another access-link connection to a 3524 switch on vlan 230.

3550 switch has ip address as 192.168.253.13 and default gateway 192.168.253.1 (core 2) and no SVI for vlan230.

I am trying to connect a host on 3550 swi in vlan 30 with static ip address and see port UP and UP but no connectevity.

Q1. On my host i am using a default gateway as 192.168.230.1. Is this a problem. if not what can be the problem?

Core 2 has route to 192.168.230.0 network. Core 2 does not any SVI for 230

I have noticed my network has lot of access link connection between switches and not trunks

Q2.What effect does this make?

Please advice

Ganesh Hariharan · ‎02-14-2010

Hi

the default gateway on 3550 is 192.168.253.1(core 2) and not 192.168.230.1 (my fault agian)

so how can i fix this problem

I have access connection of vlan 253 from 3550 to core 2

and another access connection of vlan 230 to 3524 SWI

Traceroute 192.168.230.5 first hits core 2 and goes ahead to destination

3550 does not have SVI for vlan 230 and nor does Core 2?

on core 2 i do see a route of 192.168.230.0(ospf) via vlan 253 when i do a show ip route

please advice

Hi,

I think you should not do any changes because vlan 253 subnet is reachable via core 2 to switch 3550 and i have already told you that you need to discuss your entire network topology before doing any routing changes and need to finalise how the traffic will be moved between vlans.

With the current setup switch 3550 is able to ping vlan 253 ip address that is 192.168.230.5 via core 2,so your query in the thread is solved i suppose.

If you have any other query please feel to ask us !!

Hope to help !!

Ganesh.H

gurkamal01 · ‎02-14-2010

Hi Ganesh,

Nobody has a information how traffic is sent in this network . Our Network is all messed up and i am tryng to get it straight.All i need is you guys help and that i why i come to this forum and reate it when i get a correct answer.

Previous in this thread i was informed the following which creates confusion in my mind!

" SW1 <--- VLAN 253 ----> SW2

SW1 has vlan 10
SW2 has vlan 11

for any clients in vlan 10 to communicate with clients in vlan 11 you would need to route them across the vlan 253 link.

SW1 would need a L3 SVI for vlan 10 and a L3 SVI for vlan 253
SW2 would need a L3 SVI for vlan 11 and a L3 SVI for vlan 253

HI is in vlan 10
H2 is in vlan 11

H1 sends a packet to it's default-gateway which is the IP address of SVI for vlan 10. SW1 then routes the packet to vlan 253 and the packet is switched across the vlan 253 interconnect. When it arrives at SW2, SW2 routes the packet onto vlan 11 and to H2."

Q1 My question as nformed above is the 3550 does not have an SVI for vlan 230 and core 2 also doesnt have and SVI for vlan 230

only an access connection of vlan 230 goes from 3550 to Core 2. How is traffic going to core 2 and ahead when there is no SVI on both Core 2 and 3550 ?

I did a trace for 192.168.230.1 (vlan 230)and hits the core 2 and goes ahead . 3550 also has an access connection in vlan 230 to 3524.

The dafult gateway on 3550 is 192.168.253.1 (core 2) address.

Q2.why is traffic not going from 3550 to 3524 when i do a trace route.

Please advice

Jon Marshall · ‎02-14-2010

Q1 My question as informed above is the 3550 does not have an SVI for vlan 230 and core 2 also doesnt have and SVI for vlan 230

only an access connection of vlan 230 goes from 3550 to Core 2. How is traffic going to core 2 and ahead when there is no SVI on both Core 2 and 3550 ?

You do not need an SVI to forward traffic in the same vlan ie.

H1 (vlan 10 ) -> SW1 <-- vlan 10 --> SW2 <--- vlan 10 ---> SW3 <--- vlan 10 ---> SW4 -> H2 (vlan 10)

in the above both H1 & H2 are in vlan 10. For H1 to talk to H2 and vice-versa you do not need an SVI anywhere for vlan 10. The traffic will simply be switched at L2 from SW1 to SW2 to SW3 and to SW4

H1 (vlan 10) -> SW1 <--- vlan 10 ---> SW2 <--- vlan 10 ---> SW3 <--- vlan 10 ---> SW4 -> H2 (vlan 11)

In the above H1 is in vlan 10 and H2 in vlan 11.

SW4 has L3 SVI for vlan 10 and vlan 11. For H1 to talk to H2, H1 has to send the traffic to it's default-gateway. The default-gateway on H1 would be the L3 SVI for vlan 10 on SW4. So traffic goes to SW4 vlan 10 SVI. SW4 then routes the packet to H2 on vlan 11.

Key thing to note is that you need SVIs for both vlan 10 and vlan 11 for H1 & H2 to communicate. Also you only need one SVI for vlan 10 ie. you don't need an SVI on all the intermediate switches because you are not routing the traffic to SW4, you are switching the traffic at L2.

Your network is not setup in an optimal way as far as i can see but to change it you need to have an overall design/idea of how you want it to be. If you make individual changes on individual switches then it will not get better but even more complicated. By all means ask as many questions as you need on this forum but you do need to have an idea of where you are and where you want to be for us to help you properly.

Jon

gurkamal01 · ‎02-14-2010

Thanks again

Jon

I just mad a typo in the earler post

Q1 My question as informed above is the 3550 does not have an SVI for vlan 230 and core 2 also doesnt have and SVI for vlan 230

only an access connection of vlan 230 goes from 3550 to Core 2. How is traffic going to core 2 and ahead when there is no SVI on both Core 2 and 3550 ?

Vlan 253 goes from 3550 to core 2 not vlan 230

vlan 230 access connection goes from 3550 to 3524

I would lke ask the folloeing question agian.

Q1 How is traffic going to core 2 and ahead when there is no SVI on both Core 2 and 3550 ?

I did a trace for 192.168.230.1 (vlan 230)and hits the core 2 and goes ahead . 3550 also has an access connection in vlan 230 to 3524.

The dafult gateway on 3550 is 192.168.253.1 (core 2) address.

Q2.why is traffic not going from 3550 to 3524 when i do a trace route

Thanks

gurkamal01 · ‎02-14-2010

Please advice on this

I just mad a typo in the earler post

Q1 My question as informed above is the 3550 does not have an SVI for vlan 230 and core 2 also doesnt have and SVI for vlan 230

only an access connection of vlan 230 goes from 3550 to Core 2. How is traffic going to core 2 and ahead when there is no SVI on both Core 2 and 3550 ?

Vlan 253 goes from 3550 to core 2 not vlan 230

vlan 230 access connection goes from 3550 to 3524

I would lke ask the folloeing question agian.

Q1 How is traffic going to core 2 and ahead when there is no SVI on both Core 2 and 3550 ?

I did a trace for 192.168.230.1 (vlan 230)and hits the core 2 and goes ahead . 3550 also has an access connection in vlan 230 to 3524.

The dafult gateway on 3550 is 192.168.253.1 (core 2) address.

Q2.why is traffic not going from 3550 to 3524 when i do a trace route

Thanks