Troubleshooting a switch to switch connection issue

[Process153]

Hello all,

I have been struggling  to get a resolution for a problem I have with a Cisco SF302-80p connecting to a Cisco  2801 and hope I might get a hint or two here.
Problem:

I need to uplink the sf 302's gi int to the fe int on the 2801 and allow vlan tagging for 3 vlans.
When I connect the ports with a straight cable,  I can see the mac address of the 302 when I do sh cdp nei but if I do sh arp, I see an incomplete address.

I want to host data and voice across the trunk (which has been created for each port)

When I connect the ports, I cannot ping the 302

Any help is great appreciated!
I need to get this working for Tuesday but I am at a lost as to why its not.....  I will post configs if required!

[devils_advocate]

Yep post configs, its the easiest way to see what is going on

[Process153]

Ok Thanks!  I'll get them up ASAP

[Process153]

The output is not exactly readable....... Is there a switch that will format the output?  Just using tftp and saving it to text file. :)

[Carlos Villagran]

Hi!

Have you tried a Router-on-a-stick (ROAS) configuration in the router?. What you are going to do is a trunk connection between the router and the switch and will permit the x,y,z VLANS to traverse over it.

Please refer to the following link for detailed configurations:

http://www.cisco.com/c/en/us/support/docs/lan-switching/inter-vlan-routing/14976-50.html

Let me know it it worked!

Hope it helps, best regards!

[Process153]

Hi Carlos,

That's pretty much what I was going for but for some reason, its not working...

Int on the 2800 includes:

interface FastEthernet0/0
description [ Trunk to Switch ]
no ip address
no ip redirects
no ip unreachables
ip flow ingress
duplex auto
speed auto
no mop enabled
!
interface FastEthernet0/0.1
!
interface FastEthernet0/0.2
description [ Subnet for Data ]
encapsulation dot1Q 2
no ip redirects
no ip unreachables
ip flow ingress
ip nat inside
no snmp trap link-status
!
interface FastEthernet0/0.701
description [ Subnet for IP Phones ]
encapsulation dot1Q 701
no ip redirects
no ip unreachables
ip flow ingress
ip nat inside
no snmp trap link-status

Interface on the Sf302 gi port is

switchname...#show interface switchport GigabitEthernet 1
Port : gi1
Port Mode: Trunk
Gvrp Status: disabled
Ingress Filtering: true
Acceptable Frame Type: admitAll
Ingress UnTagged VLAN ( NATIVE ): 999

Port is member in:

Vlan               Name               Egress rule Port Membership Type
---- -------------------------------- ----------- --------------------
 2                  2                   Tagged           Static
701               VOICE                 Tagged           Static
999               TRUNK                Untagged          Static

Forbidden VLANS:
Vlan               Name
---- --------------------------------

Is that enough guys???

[Carlos Villagran]

Hi!

The sub-interfaces do not have IP addresses configured!

Please configure them an IP address within the same subnet and it should work.

Hope it helps, best regards!

JC

[Process153]

Hi!

So if the interface of vlan 2 was 50.30.0.23 /16, I'd need to configure that on the sub interface on port 0/0?  And then do this for each vlan?

[glen.grant]

  If doing router on a stick and the 2800 is doing the routing then yes each subinterface needs an ip address on and all devices in that vlan would use that address as their default gateway off the subnet .

[Process153]

Ah that makes sense! Thanks Glen.

[Carlos Villagran]

Hi!

Yes, please configure an IP Address in each sub-interface according to the VLAN subnet. 

I.E:

interface FastEthernet0/0.1
!
interface FastEthernet0/0.2
description [ Subnet for Data ]
encapsulation dot1Q 2

ip address 10.1.1.10 255.255.255.0    <<<<   VLAN 1 Subnet 10.1.1.0/24
no ip redirects
no ip unreachables
ip flow ingress
ip nat inside
no snmp trap link-status
!

Hope it helps, best regards!

JC

[Process153]

Many thanks Carlos!  I will not be able to test this until Tuesday but hopefully that will be the reason.

[Process153]

Just in case anyone else is following this it looks like there is a problem with the configuration of the 2600.  This was done externally.  I am now seeing a similar problem affecting another router configured by the external.  It makes sense as I was able to get transport working across other sites and just could figure out why the same logic was not working in the above examples.

Will spend some time working on this and report my findings.  Hopefully they will help someone else.

[Process153]

Hi Carlos,

Being a bit dim here but do I need to have subinterfaces configured on both switches for this to work or can i leave the sf as just a .1q trunk?

Thanks!

[Carlos Villagran]

Hi!

With your trunk interface connected to the router and the VLANs created in the switch you are good to go, there is no need for anything else.

Please let me know how it went, best regards!

JC