connection between distribution sw to router

Unanswered Question

hi!

I've a pair of 3550 sw runnig hsrp. The 3550 distrution switches are the route processor/gw for intervlan routing. If i would to connect 2x 2811 routers to our hq (1 router connection from each dist sw), what would be the recommended or normal configuration like? can provide sample guideline on this? is it active, standby and how can i determine the priority path etc?

one question is that the ethernet connection from my 3550 switch to the 2811 routers' ethernet connection, shd it be a trunk link or i've to configure that port to be L3 with the no switcport command and then assign it with an ip on the sw end and the router end?

thx.

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Overall Rating: 4 (3 ratings)
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Jon Marshall Tue, 06/01/2010 - 10:33

Depends what you want but personally i would use routed point to point links between the 3550s and 2800 routers and run a dynamic routing protocol between them. Then leave it up to the dynamic routing protocol work out which link to use.

Jon

merryllem Tue, 06/01/2010 - 10:46

Hello,

From what I can tell from your post, you need to add 2x RTR's to your network to connect to your HQ. I am assuming 2X WAN (P2P/MPLS/Frame) connections. In most instances when more than one connection is present you would use a routing protocol to provide the load balacing and failover of the connection (Using HSRP is also plausible). I can't really give you examples until you clarify what you are trying to do.(Diagrams would be nice)

For the second question, you have multiple options to connect your router, the most common way is just to create a new VLAN/Subnet (on the switch) and connect the RTR ethernet to the switch using an switch access port. This option gives you the flexibility to use a routing protocol or HRSP on the switch end to achive LB or Failover.

Using trunks on RTR ports is used mostly for a VLAN on a stick topology. In your case, I think  you not would gain anything by using trunks.

Hope that helps

hi! I'm trying this out in the test environment first. The WAN link i'm using in the test environment is a p2p link whereas the actual env is running mpls. This is to simplify the test setup. I would just want to get the concept right first. A bit of guideline and sample will be great. i;ve attached the draft of the setup. i hope to have at least a active/standby(branch router) of setup for the traffic to the hq. thx

Attachment: 
tj.mitchell Tue, 06/01/2010 - 11:05

PTP links with a protocol between them. criss/cross the links if possible R1 to Sw1 and R1 to Sw2, then R2 to Sw2 and R2 to Sw1. Then connect the switches together. Use a protocol between the router/switch links and what ever you want between the switches. Give you load-balance and redundancy.

merryllem Wed, 06/02/2010 - 11:15

You need to find out how you and your ISP will handle routing (Thru Routing Protocls or Static Routes).

With that said, here are a few things to get you started

Lets assume the following information

HQ Subnet: 7.7.7.0 255.255.255.0
Branch Subnet:8.8.8.0 255.255.255.0

HQ1

interface s0/0
ip address 1.1.1.1 255.255.255.252

ip route 8.8.8.0 255.255.255.0 1.1.1.2

HQ2

interface s0/0
ip address 2.2.2.1 255.255.255.252

ip route 8.8.8.0 255.255.255.0 2.2.2.2.2


Branch1

interface s0/0
ip address 1.1.1.2 255.255.255.252

interface F0/0
ip address 3.3.3.1 255.255.255.248

ip route 7.7.7.0 255.255.255.0 1.1.1.1

router ospf 10
network 3.3.3.0 0.0.0.7 area 0
redistribute static subnets

Branch2

interface s0/0
ip address 2.2.2.2 255.255.255.252

interface F0/0
ip address 3.3.3.2 255.255.255.248

ip route 7.7.7.0 255.255.255.0 2.2.2.1

router ospf 10
network 3.3.3.0 0.0.0.7 area 0
redistribute static subnets

DL-SW1

Interface VLAN333
ip address 3.3.3.3 255.255.255.248

Interface fa0/20
Switchport mode access
switchport acces vlan 333

router ospf 10
passive-interface default
no pass-interface VLAN333
network 3.3.3.0 0.0.0.7 area 0
network 8.8.8.0 0.0.0.7 area 0

DL-SW2

Interface VLAN333
ip address 3.3.3.4 255.255.255.248

Interface fa0/20
Switchport mode access
switchport acces vlan 333

router ospf 10
passive-interface default
no pass-interface VLAN333
network 3.3.3.0 0.0.0.7 area 0
network 8.8.8.0 0.0.0.7 area 0

Hope that helps

hi! Thanks for the reply.

I setup the lab environment using the IPs that you gave me as an example, except that i added in the 172.16.x.x range in the DL-switch1 and a loopback interface at the HQ1 (I tried in HQ1 and Branch1 first). In addition to that, my test env DL-switch1 can only run eigrp. Based on the config that i've done below, what need to be done so that from my DL-switch1 i can reach the loopback interface at HQ1 and vice versa? With the config below from my DL-switch1 i can only reach Branch1's fa0/0 interface. and from my HQ1 i can only reach the vlan333 interface but not the rest of the interfaces. pls advise. thanks!

HQ1
-------------------
interface Loopback10

ip address 8.8.8.1 255.0.0.0
!
interface FastEthernet0/0
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0/0
ip address 1.1.1.1 255.255.255.252
!
interface Serial0/1/0
no ip address
shutdown
clock rate 2000000
!
ip forward-protocol nd
ip route 3.3.3.0 255.255.255.248 1.1.1.2
ip route 172.16.10.0 255.255.255.0 1.1.1.2
ip route 172.16.11.0 255.255.255.0 1.1.1.2
ip route 172.16.12.0 255.255.255.0 1.1.1.2
ip route 172.16.13.0 255.255.255.0 1.1.1.2
ip route 172.16.14.0 255.255.255.0 1.1.1.2
ip route 172.16.15.0 255.255.255.0 1.1.1.2


----------------------------------------------

branch1
----------
interface FastEthernet0/0
ip address 3.3.3.1 255.255.255.248
duplex auto
speed auto
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0/0
ip address 1.1.1.2 255.255.255.252
clock rate 64000
!
router ospf 10
log-adjacency-changes
redistribute static subnets
redistribute eigrp 10 metric 1 subnets
network 3.3.3.0 0.0.0.7 area 0
!
ip classless
ip route 0.0.0.0 0.0.0.0 1.1.1.1
ip route 3.3.3.0 255.255.255.248 FastEthernet0/0
ip route 172.16.15.0 255.255.255.0 FastEthernet0/0
!
no ip http server
no ip http secure-server
!
!
!
control-plane
!
!
!
line con 0
line aux 0
line vty 0 4
login
!
scheduler allocate 20000 1000
!
end
---------------------------------------------------
DL-Switch1
----------
!
interface Vlan333
ip address 3.3.3.3 255.255.255.248
!
router eigrp 10
network 3.3.3.0 0.0.0.7
network 172.16.10.0 0.0.0.255
network 172.16.11.0 0.0.0.255
network 172.16.12.0 0.0.0.255
network 172.16.13.0 0.0.0.255
network 172.16.14.0 0.0.0.255
network 172.16.15.0 0.0.0.255
no auto-summary

merryllem Thu, 06/03/2010 - 11:20

Looks like EIGRP needs to be configured on the branch router. Here are the lines

branch1

!*remove the following lines since there is no need for it
no ip route  3.3.3.0 255.255.255.248 FastEthernet0/0
no ip route 172.16.15.0  255.255.255.0 FastEthernet0/0

router eigrp 10
network 3.3.3.0 0.0.0.7

redistribute static

default-metric 1500 1 255 1 1500
  no auto-summary

Hope that helps

merryllem Mon, 06/07/2010 - 12:58

So what you are asking is to run EIGRP on the switch and OSPF in the router?

In order for the DL-Swtich and the Branch1 Router to exchange routes they need to use the same routing protocol. With that said, what you are asking is not possible.

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