Need help with connection with L3 interface on diffferent swit

[Damon2021]

Hi,

I have a connection like below:

So I have a network connection like this. I am trying to get my PC connected to VLAN 50. However, I am not getting any connection and can not ping the gateway. I can not ping gateway even from L3 Switch 2 to VLAN interface of L3 Switch 1. Please advice.

All the link to core and switches are working and advertised in ospf on both end. I can connect PC to switch 1 and it works. I tried

Ip default gateway <VLAN 50 Interface IP> 

on switch 2 but that did not work.

[balaji.bandi]

Switch 1 to Switch 2 Layer 2 connection Only, then PC connected port below to access port vlan 50, then PC able to ping the gateway.

From switch1 , so you see

arp table show IP arp

( do you see ARP entry of PC?)

Can you post the below information from switch 1 and switch 2

show vlan

show IP interface brief

show run interface x/x (trunk port config)

Pc - connected port show run interface x/x

[Damon2021]

From Sw1, I see arp but it shows incomplete. 

Internet 10.150.5.5 0 Incomplete ARPA




Sh vlan:

VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
50 V50_Mgmt active Te1/0/8, Te1/0/9




Trunk:

interface TenGigabitEthernet1/0/14
switchport trunk allowed vlan 50
switchport mode trunk
end

Int bri:

Te1/0/9 unassigned YES unset up up




PC Port:

interface TenGigabitEthernet1/0/9
switchport access vlan 50
switchport mode access
end




Sh int trunk:

Te1/0/14 on 802.1q trunking 1

Port Vlans allowed on trunk
Te1/0/14 50

Port Vlans allowed and active in management domain
Te1/0/14 50

Port Vlans in spanning tree forwarding state and not pruned
Te1/0/14 none

[balaji.bandi]

here is my observervation :

as per the PC IP 10.10.50.5 - but you mesage below :

From Sw1, I see arp but it shows incomplete. 

Internet 10.150.5.5 0 Incomplete ARPA    <<<<- is this correct IP ?

if you have Trunk, one of the reply what is the blocked ? that means you have spanning loop in the network, that is the reason PC not able to reach the gateway.

becuase they are not communicating each other, VLAN 50 root on both the switches ?

[Damon2021]

Hi,

I copied the wrong line. Here is the line.

Internet 10.10.50.5 0 Incomplete ARPA

This VLAN is just on these two switches. How can there be a loop? Any idea how to fix?

This VLAN 50 is not trunked up to the Core. The switches and core links just have the p2p vlan 3100/3200.

[balaji.bandi]

show spanning block - from both the switches ?

check below your output :

Switch 1:




VLAN050
Spanning tree enabled protocol rstp
Root ID Priority 32871
Address 0001.0202.aabb
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32871 (priority 32768 sys-id-ext 50)
Address 0001.0202.aabb
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Te1/0/9 Desg FWD 4 128.9 P2p 
Te1/0/14 Desg FWD 2 128.14 P2p




Switch 2:




VLAN050
Spanning tree enabled protocol rstp
Root ID Priority 32871
Address 0001.0202.aabb
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32871 (priority 32768 sys-id-ext 50)
Address 0001.0202.aabb
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Te1/0/9 Desg FWD 4 128.9 P2p 
Te1/0/14 Back BLK 2 128.14 P2p

[Seb Rupik]

Hi there,

What is the output of

sh spanning-tree vlan 50

  and

sh mac-address-table vlan 50 

on the two L3 switches? What does the switchport config look like on the port the PC is connected to? What is the MAC address of the PC?

cheers,

Seb.

[Damon2021]

Switch 1:




VLAN050
Spanning tree enabled protocol rstp
Root ID Priority 32871
Address 0001.0202.aabb
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32871 (priority 32768 sys-id-ext 50)
Address 0001.0202.aabb
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Te1/0/9 Desg FWD 4 128.9 P2p 
Te1/0/14 Desg FWD 2 128.14 P2p




Switch 2:




VLAN050
Spanning tree enabled protocol rstp
Root ID Priority 32871
Address 0001.0202.aabb
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32871 (priority 32768 sys-id-ext 50)
Address 0001.0202.aabb
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Te1/0/9 Desg FWD 4 128.9 P2p 
Te1/0/14 Back BLK 2 128.14 P2p

[Jon Marshall]

Both switches are claiming to be the root switch which isn't right. 

Also from your previous post showing the trunk link (on switch 2 ?) vlan 50 is not forwarding on te1/0/14 which I assume is the connection to switch 1 ? 

Have you allowed vlan 50 on switch 1 trunk link ? 

Jon

[Damon2021]

Yes, te1/0/14 is the interlink. Here is output from both switches:

Switch 1:




Port Mode Encapsulation Status Native vlan 
Te1/0/1 on 802.1q trunking 1
Te1/0/14 on 802.1q trunking 1

Port Vlans allowed on trunk
Te1/0/14 50

Port Vlans allowed and active in management domain
Te1/0/14 50

Port Vlans in spanning tree forwarding state and not pruned
Te1/0/14 50




Switch 2:




Port Mode Encapsulation Status Native vlan 
Te1/0/1 on 802.1q trunking 1
Te1/0/14 on 802.1q trunking 1

Port Vlans allowed on trunk
Te1/0/14 50

Port Vlans allowed and active in management domain
Te1/0/14 50

Port Vlans in spanning tree forwarding state and not pruned
Te1/0/14 none

[Damon2021 · Accepted solution]

Issue fixed.

It was related to below issue:

LACP failing between 2 C9500-16X switches

Basically, both switches had the same mac and it created an issue with stp where both became root and one side of the trunk was blocked.

[Seb Rupik]

Hi there,

Can you confirm the physical connection for Switch2 Te1/0/14. The STP output shows this port as a BACKUP port which indicates that it is receiving its own BPDU which we can assume is being sent via Te1/0/9 .

cheers,

Seb.

[Flavio Miranda]

Hi

 Did you create vlan 50 on switch 2 and switch 1? command 'vlan 50'

[Damon2021]

Yes