New WS-C3850-48XS and VoIP telephone stopped working.

[Robert Rauch]

Hello,

I have just tried to migrate a 3 stack C3750G-12S to a C3850-48XS

The configuration was the same for the interfaces, was also told to leave the class-map as default on the 3850.

Anyway, the migration went well for all the access switches that were migrated to the new distribution switch. Had no real problems and all access switch where reachable again.

The problem that we realised a little later was the VoIP telephone started rebooting and could no longer reach the PABX tftp server anymore. It was required to return to the old 3750 switches until this issue is resolved. 

Arhitecture

VoIP telephone ==> Access switch ==> 3750 stack / migrate to 3850.

My question, can this have to do with the default class map on the 3850, the voice vlan was being trunked.

These are the default class maps and default interface config on the 3850

class-map match-any system-cpp-police-topology-control
description Topology control
class-map match-any system-cpp-police-sw-forward
description Sw forwarding, SGT Cache Full, LOGGING
class-map match-any system-cpp-default
description DHCP snooping, show forward and rest of traffic
class-map match-any system-cpp-police-sys-data
description Learning cache ovfl, Crypto Control, Exception, EGR Exception, NFL SAMPLED DATA, Gold Pkt, RPF Failed
class-map match-any system-cpp-police-punt-webauth
description Punt Webauth
class-map match-any system-cpp-police-forus
description Forus Address resolution and Forus traffic
class-map match-any system-cpp-police-multicast-end-station
description MCAST END STATION
class-map match-any system-cpp-police-multicast
description Transit Traffic and MCAST Data
class-map match-any system-cpp-police-l2-control
description L2 control
class-map match-any system-cpp-police-dot1x-auth
description DOT1X Auth
class-map match-any system-cpp-police-data
description ICMP_GEN and BROADCAST
class-map match-any system-cpp-police-control-low-priority
description ICMP redirect and general punt
class-map match-any system-cpp-police-wireless-priority1
description Wireless priority 1
class-map match-any system-cpp-police-wireless-priority2
description Wireless priority 2
class-map match-any system-cpp-police-wireless-priority3-4-5
description Wireless priority 3,4 and 5
class-map match-any non-client-nrt-class
class-map match-any system-cpp-police-routing-control
description Routing control
class-map match-any system-cpp-police-protocol-snooping
description Protocol snooping
!
policy-map port_child_policy
class non-client-nrt-class
bandwidth remaining ratio 10
policy-map system-cpp-policy
class system-cpp-police-data
police rate 200 pps
class system-cpp-police-sys-data
police rate 100 pps
class system-cpp-police-sw-forward
police rate 1000 pps
class system-cpp-police-multicast
police rate 500 pps
class system-cpp-police-multicast-end-station
police rate 2000 pps
class system-cpp-police-punt-webauth
class system-cpp-police-l2-control
class system-cpp-police-routing-control
police rate 1800 pps
class system-cpp-police-control-low-priority
class system-cpp-police-wireless-priority1
class system-cpp-police-wireless-priority2
class system-cpp-police-wireless-priority3-4-5
class system-cpp-police-topology-control
class system-cpp-police-dot1x-auth
class system-cpp-police-protocol-snooping
class system-cpp-police-forus
class system-cpp-default
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface Port-channel44
description wspcr2xx
switchport trunk native vlan 702
switchport trunk allowed vlan 2-4094
switchport mode trunk
switchport nonegotiate
logging event trunk-status
!
interface GigabitEthernet0/0
vrf forwarding Mgmt-vrf
no ip address
shutdown
negotiation auto
!
interface FortyGigabitEthernet1/1/1
shutdown
!
interface FortyGigabitEthernet1/1/2
shutdown
!
interface FortyGigabitEthernet1/1/3
shutdown
!
interface FortyGigabitEthernet1/1/4
shutdown
!
interface TenGigabitEthernet1/0/1
switchport trunk native vlan 702
switchport trunk allowed vlan 2-4094
switchport mode trunk
duplex auto
storm-control broadcast level pps 1k
!
interface TenGigabitEthernet1/0/2
switchport trunk native vlan 702
switchport trunk allowed vlan 2-4094
switchport mode trunk
duplex auto
storm-control broadcast level pps 1k
!
interface TenGigabitEthernet1/0/3
switchport trunk native vlan 702
switchport trunk allowed vlan 2-4094
switchport mode trunk
duplex auto
storm-control broadcast level pps 1k
!

Default interface config 3750

interface GigabitEthernet1/0/4
switchport trunk encapsulation dot1q
switchport trunk native vlan 702
switchport trunk allowed vlan 2-4094
switchport mode trunk
storm-control broadcast level pps 1k

Any ideas why the VoIP telephone stared to reset?

br

Robert

[johnd2310]

Hi,

 Were the phones getting an ip address but just not connecting to the PBX? Were the PCs working okay? What ios version was running on the 3850?

Thanks

John

[Robert Rauch]

Hi John,

Switch Ports Model SW Version SW Image Mode
------ ----- ----- ---------- ---------- ----
* 1 68 WS-C3850-48XS 16.3.3 CAT3K_CAA-UNIVERSALK9 INSTALL

PC where working OK as far as I know.

Not sure if the phones where getting or still had their previous IP, but they could not reach the TFTP server on the pabx.

I had to revert after 1/2 hour due to all the users were coming to work. Am still analyzing now.

Robert

[brselzer]

Hello Robert,

The default class maps you see are actually for CoPP to protect your CPU. They should not impact traffic going through your box, only traffic going to the CPU. I am pretty confident they are not the source of your issue. 

It will be tough to say without more logs but as mentioned before, either you were not getting an ip or there was some other reason you could not reach the device.

Is the TFTP server in the same subnet as the phones or is the 3850 routing between vlans?

[Robert Rauch]

Hello Bradley,

Yes, I understand because I didnt have enough time to trouble shoot before reverting the arhitecture back to the stacks 3750's.

The TFTP server from the pabx is in a different network, the new switch with is still reachable from management and I can reach the pabx tftp with ping.

I plan to add a small catalyst 2960 to the 3850 with the same setup as our access switches, this I will add a VoIP telephone and see if I can get any additional information.

Plan to do this today.

Robert

[Robert Rauch]

Hello Bradley,

OK, some extra facts.

Just added a WS-C2960C-8PC-L small switch to the WS-C3850-48XS to TS a little more.

I could not even get an IP address via DHCP so I didnot even try the VoIP telephone.

The 3850 is just a distrubution switch, L2, our nexus do the routing. I added the 2960 to the existing 3750 stack switch and the DHCP worked straight away.

Im missing something on these new switches, Have checked the nexus config and that looks fine and is also working wit the 3750 stacks, have 2 stacks of 3 also just switching.

I also saw all the vlans from the VTP domain on the 2960, also the voice vlan. Ping voice vlan also works from the 2960 from both switches, 2960 can also be reached from remote, looks completely intergrated.

Any tips.

slowley running out of ideas.

Robert

[brselzer]

Hello Robert,

I know this is silly but the 3850 ships without ip routing enabled. You might want to double check that is on. "show run | inc routing".

Do you have a helper address configured on the 3850? If you plug a laptop into the voice vlan (switchport access vlan [voice vlan]) and give it a static ip, can you ping the DHCP server?

Hope that helps. Thanks!

[johnd2310]

Hi,

Is vtp working on the 3850s? Can you see the vlans on the 3850s. check that spanning tree for all vlans on the 3850s is correct. Try another ios version like 16.3.5b

Thanks

John

[Robert Rauch]

yippee ki yay

Got it working, with my first tests anyway.

Yes, VTP was working. Even could find mac address from my devices but no DHCP would work.

Solution was upgrade to the 16.6.2. First tests all worked, DHCP, VoIP phones. Will do a few more tests tomorrow before I migrate the old links to new switch.

Still dont exactly know why it wasnt working. Old version was the shipped version 6.03.03

:))

Robert

thanks for all the suggestions that helped me with TS

[Robert Rauch]

typo mistake 16.03.03 was the old version...