Trunk port not working between C3850 and C3560X

[RookieNet55]

Hi everyone,

I have C3560X switch which is the current core, trying to add a new switch C3850-24XS via the trunk port. The link status is up, I can see the lights on both ports physically. But no communication between the switches via trunk port, no CDP neighbours either. There is VTP on both switches, C3560X is server and C3850 is configured as client, I have double checked the passwords and they are good.

Any help is appreciated on getting this trunk up and running. I can provide more config info as required.

Below are some configurations.

C3560X side

ip routing

interface Vlan100
description Management VLAN
ip address 172.18.100.1 255.255.255.0

interface GigabitEthernet0/24
switchport trunk encapsulation dot1q
switchport trunk native vlan 100
switchport trunk allowed vlan 100
switchport mode trunk

sh int gi0/24 status

Port Name Status Vlan Duplex Speed Type
Gi0/24 new san test connected trunk a-full a-1000 10/100/1000BaseTX

VTP Version                     : running VTP2
Configuration Revision          : 17
Maximum VLANs supported locally : 1005
Number of existing VLANs        : 15
VTP Operating Mode              : Server
VTP Domain Name                 : CDCCORPVTP1
VTP Pruning Mode                : Disabled
VTP V2 Mode                     : Enabled
VTP Traps Generation            : Disabled
MD5 digest                      : 0x89 0x03 0xC4 0x18 0xAD 0x3D 0xAD 0xB3
Configuration last modified by 0.0.0.0 at 3-1-93 00:20:35
Local updater ID is 172.18.2.1 on interface Vl2 (lowest numbered VLAN interface found)

C3850 side

ip routing

interface Vlan100
ip address 172.18.100.9 255.255.255.0
!
ip route 0.0.0.0 0.0.0.0 172.18.100.1

interface TenGigabitEthernet1/0/24
switchport trunk native vlan 100
switchport trunk allowed vlan 100
switchport mode trunk

sh int te1/0/24 status

Port Name Status Vlan Duplex Speed Type
Te1/0/24 connected trunk a-full a-1000 10/100/1000BaseTX SFP

sh vtp status
VTP Version capable             : 1 to 3
VTP version running             : 2
VTP Domain Name                 : CDCCORPVTP1
VTP Pruning Mode                : Disabled
VTP Traps Generation            : Disabled
Device ID                       : 0056.2bd9.1e80
Configuration last modified by 172.18.100.9 at 12-21-23 21:55:55

Feature VLAN:
--------------
VTP Operating Mode                : Client
Maximum VLANs supported locally   : 1005
Number of existing VLANs          : 7
Configuration Revision            : 0
MD5 digest                        : 0xB3 0x4C 0x27 0x65 0xCD 0x6D 0x7D 0x1C
                                    0xAF 0x5B 0x02 0x3A 0x60 0x47 0xA0 0xAF

[marce1000]

              - Check logs on both devices when  trunk is being made ,

 M.

[RookieNet55]

Would you be guide me on how to check that ? Thanks you

[balaji.bandi]

Server says Number of vlan 15 and new switch show only 7 ?

If you shutdown one of the side interface admin down, Hope other side same connected interface go down ? (just to confirm plugged in right ports ?)

Can you try on the new switch VTP mode Transparent and add VLAN 100 Manually and test is that works ?

show vlan (check VLAN 100 exists)

show spanning vlan 100

show ip interface brief (check vlan 100 iSVI )interface up 

[RookieNet55]

I tried changing the VTP to transperent on client side (C3850) but that didn't work

More outputs on C3850

sh spanning-tree vlan 100

VLAN0100
  Spanning tree enabled protocol rstp
  Root ID    Priority    32868
             Address     0056.2bd9.1e80
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32868  (priority 32768 sys-id-ext 100)
             Address     0056.2bd9.1e80
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time  300 sec

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Te1/0/24            Desg FWD 4         128.24   P2p

sh vlan br

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Te1/0/5, Te1/0/6, Te1/0/7, Te1/0/8, Te1/0/9, Te1/0/10, Te1/0/11, Te1/0/12, Te1/0/17
                                                Te1/0/18, Te1/0/19, Te1/0/20, Te1/0/21, Te1/0/22, Te1/0/23
52   VLAN0052                         active    Te1/0/1, Te1/0/2, Te1/0/3, Te1/0/4, Te1/0/13, Te1/0/14, Te1/0/15, Te1/0/16
100  VLAN0100                         active
1002 fddi-default                     act/unsup
1003 trcrf-default                    act/unsup
1004 fddinet-default                  act/unsup
1005 trbrf-default                    act/unsup

sh ip int vlan 100
Vlan100 is up, line protocol is up
  Internet address is 172.18.100.9/24
  Broadcast address is 255.255.255.255
  Address determined by non-volatile memory
  MTU is 1500 bytes
  Helper address is not set
  Directed broadcast forwarding is disabled
  Outgoing Common access list is not set
  Outgoing access list is not set
  Inbound Common access list is not set
  Inbound  access list is not set
  Proxy ARP is enabled
  Local Proxy ARP is disabled
  Security level is default
  Split horizon is enabled
  ICMP redirects are always sent
  ICMP unreachables are always sent
  ICMP mask replies are never sent
  IP fast switching is enabled
  IP Flow switching is disabled
  IP CEF switching is enabled
  IP CEF switching turbo vector
  IP Null turbo vector
  Associated unicast routing topologies:
        Topology "base", operation state is UP
  IP multicast fast switching is enabled
  IP multicast distributed fast switching is disabled
  IP route-cache flags are Fast, CEF
  Router Discovery is disabled
  IP output packet accounting is disabled
  IP access violation accounting is disabled
  TCP/IP header compression is disabled
  RTP/IP header compression is disabled
  Probe proxy name replies are disabled
  Policy routing is disabled
  Network address translation is disabled
  BGP Policy Mapping is disabled
  Input features: MCI Check
  IPv4 WCCP Redirect outbound is disabled
  IPv4 WCCP Redirect inbound is disabled
  IPv4 WCCP Redirect exclude is disabled

[Leo Laohoo]

---

@RookieNet55 wrote:
no CDP neighbours either

---

What is the uptime of the 3850 switch and what firmware is the 3850 running on?

[RookieNet55]

Uptime is about 3 days. C3850 is running on 16.12.10a

[balaji.bandi]

how come you have VLAN 100 root here : it suppose to be root on at 3650 since that is already holding VLAN 100 ?

This bridge is the root

what you see on Cat 3650 ?

sh spanning-tree vlan 100

show interface  Te1/0/24 switchport  (from Cat 3850)

show interface  Te1/0/24

show interface  GigabitEthernet0/24  switchport  (from Cat 3650)

show interface  GigabitEthernet0/24

[RookieNet55]

So what I did was before putting this C3850 switch on VTP, I created vlan 100 manually on this switch. So this switch can communicate over the trunk with vlan 100 and get all the VTP information. Would this be causing any conflict.

Fw more details, I beleive there is no layer 2 communication at all at this point, though physical link is good per "sh interface command". No CDP neighbours and also no arp entries.

Below are requested command outputs

On C3850

sh int te1/0/24 switchport
Name: Te1/0/24
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: trunk
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: dot1q
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 100 (VLAN0100)
Administrative Native VLAN tagging: disabled
Voice VLAN: none
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk associations: none
Administrative private-vlan trunk mappings: none
Operational private-vlan: none
Trunking VLANs Enabled: 100
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL

Protected: false
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Vepa Enabled: false
Appliance trust: none

On C3650

sh int gi0/24 switchport
Name: Gi0/24
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: trunk
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: dot1q
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 100 (mgmt)
Administrative Native VLAN tagging: enabled
Voice VLAN: none
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk associations: none
Administrative private-vlan trunk mappings: none
Operational private-vlan: none
Trunking VLANs Enabled: 100
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL

Protected: false
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none

sh int gi0/24
GigabitEthernet0/24 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is 0018.7392.c618 (bia 0018.7392.c618)
  Description: new san test
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input never, output 00:00:01, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts (0 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     256773 packets output, 22913303 bytes, 0 underruns
     0 output errors, 0 collisions, 3 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

[balaji.bandi]

what you see on Cat 3650 ? (if you see on this also root - then looks like you have  Layer 2 issue.

sh spanning-tree vlan 100

To fix this : make sure VLAN 100 Root in Cat 3650 (and VLAN 100 created)

If at 3850 not in production  (remove the link between both the switches ?) - Remove all the VLANS and make VTP transparent - Write the config reload..

Once the switch come back, create vlan 100 - connect the port and test it.

[RookieNet55]

Here is what I did based on your directions
on C3850 :

• Made sure vlan 100 exists on C3560x (core server)
• Changed vtp to transparent
• removed all vlan (no vlan 100 and no vlan 52) Had only two vlans, vlan52 is not required at the moment to keep things simple.
• reload the switch
• re add the vlan 100
• tried the ping 172.18.100.1 but no luck
• Changed vtp server to client mode
• Same result, No connectivity

[balaji.bandi]

what you see on Cat 3650 ?

sh spanning-tree vlan 100

For testing can we make p2p interface and test :

Try layer 3 interface to confirm all ok :

interface  Te1/0/24 

no switchport

ip address 10.10.10.1 255.255.255.0 (make sure there no other device configured same IP)

no shutdown

Other switch

interface  GigabitEthernet0/24

no switchport

ip address 10.10.10.2 255.255.255.0

no shut

connect cables and test pinging each other 10.10.10.1 and 10.10.10.2

[RookieNet55]

out put of spanning tree on vlan 100 on C3650

VLAN0100
  Spanning tree enabled protocol ieee
  Root ID    Priority    32868
             Address     0018.7392.c600
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32868  (priority 32768 sys-id-ext 100)
             Address     0018.7392.c600
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/2               Desg FWD 4         128.2    P2p
Gi0/3               Desg FWD 4         128.3    P2p
Gi0/23              Desg FWD 4         128.23   P2p
Gi0/24              Desg FWD 4         128.24   P2p

The other ports are the other switches in production which are working fine.
When I change the port to ip address would this need a anything on the ip route, or it should work once the ports are changed to layer 3 

[balaji.bandi]

The other ports are the other switches in production which are working fine.  - Ok noted

When I change the port to ip address would this need a anything on the ip route, or it should work once the ports are changed to layer 3 

this is to prove the ports are working.

Full-duplex, 1000Mb/s, link type is auto, media type is 10/100/1000BaseTX SFP

Are sure you connected each other connected right ports ? - I have asked before, if you remove the cable other end did the port gone down ?

what is the full model of the both the switches ?

did you tried different ports ?  - changing to different ports ?

From 3850 post complete below output :

#show interface status

If the switch is ws-c3850-24

then configure using - interface GigabitEthernet1/0/24

[RookieNet55]

Are sure you connected each other connected right ports ? - I have asked before, if you remove the cable other end did the port gone down ?

yes it is connected to right ports, I shutdown the port on one side and the other side port will go down. I am not at site today, but will be tomorrow. But even then for your question, yes the ports are physically connected to the right ports.

what is the full model of the both the switches ?

Core Switch in production:
Switch Ports Model SW Version SW Image
------ ----- ----- ---------- ----------
* 1 52 WS-C3560G-48TS 12.2(46)SE C3560-ADVIPSERVICESK9-M

New switch trying to add:
Switch Ports Model              SW Version        SW Image              Mode
------ ----- -----              ----------        ----------            ----
*    1 34    WS-C3850-24XS      16.12.10a         CAT3K_CAA-UNIVERSALK9 INSTALL

sh int status

Port         Name               Status       Vlan       Duplex  Speed Type
Te1/0/1                         notconnect   52           auto   auto unknown
Te1/0/2                         notconnect   52           auto   auto unknown
Te1/0/3                         notconnect   52           auto   auto unknown
Te1/0/4                         notconnect   52           auto   auto unknown
Te1/0/5                         notconnect   1            auto   auto unknown
Te1/0/6                         notconnect   1            auto   auto unknown
Te1/0/7                         notconnect   1            auto   auto unknown
Te1/0/8                         notconnect   1            auto   auto unknown
Te1/0/9                         notconnect   1            auto   auto unknown
Te1/0/10                       notconnect   1            auto   auto unknown
Te1/0/11                       notconnect   1            auto   auto unknown
Te1/0/12                       notconnect   1            auto   auto unknown
Te1/0/13                       notconnect   52          auto   auto unknown
Te1/0/14                       notconnect   52          auto   auto unknown
Te1/0/15                       notconnect   52          auto   auto unknown
Te1/0/16                       notconnect   52          auto   auto unknown
Te1/0/17                       notconnect   1            auto   auto unknown
Te1/0/18                       notconnect   1            auto   auto unknown
Te1/0/19                       notconnect   1            auto   auto unknown
Te1/0/20                       notconnect   1            auto   auto unknown
Te1/0/21                       notconnect   1            auto   auto unknown
Te1/0/22                       notconnect   1            auto   auto unknown
Te1/0/23                       notconnect   1            auto   auto unknown
Te1/0/24                       connected    trunk      a-full a-1000 10/100/1000BaseTX SFP