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Advisor

Re: Wacky Routing issue with VLAN

  On the switchport on the 3560 on g1/0/23  try adding "switchport nonegotiate"  and report back .  It's possible that because the 3750 is a vtp server and is in a different vtp domain or no domain in the  router case  it may keep the trunk from coming up correctly .  This is the problem with hardcoding trunks as long as you have a physical link it will tell you it's trunking when it might not be .  Going to a router you have no choice but to hardcode so there is really no way around that. If this doesnt work I'm out of ideas . 

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Beginner

Re: Wacky Routing issue with VLAN

Hi, would it be possible for u to post the show run & show ip route, sh ip arp from the router and show spanning-tree vlan 172 from the switch. Also when u have a host in vlan 172 and when u try to ping the router ip do u see outbound pkts incrementing on g1/0/23. Thx

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Beginner

Re: Wacky Routing issue with VLAN

One more thing Is it possible that any of your hosts might have the same ip as your router. Can u confirm if the mac entry on your host matches the mac of the router.

Thx

Highlighted
mbj Beginner
Beginner

Re: Wacky Routing issue with VLAN

Added switchport nonnegotiate, no luck.

Beginner

Re: Wacky Routing issue with VLAN

So in summary, you're only having issues with tagged frames over a trunk.

Can you please issue a 'show interface g1/0/23 switchport' on the 3750 and a 'sh int g0/0' on the 3825.

Thanks,

Adam

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mbj Beginner
Beginner

Re: Wacky Routing issue with VLAN

Sho INT GIG0/0

MSA3800#sho int gig0/0

GigabitEthernet0/0 is up, line protocol is up

  Hardware is BCM1125 Internal MAC, address is 0023.0470.a2d0 (bia 0023.0470.a2d0)

  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 RJ45

  output flow-control is XON, input flow-control is XON

  ARP type: ARPA, ARP Timeout 04:00:00

  Last input 00:00:00, output 00:00:00, output hang never

  Last clearing of "show interface" counters never

  Input queue: 0/75/693/2 (size/max/drops/flushes); Total output drops: 155

  Queueing strategy: Class-based queueing

  Output queue: 0/1000/64/0 (size/max total/threshold/drops)

     Conversations  0/23/256 (active/max active/max total)

     Reserved Conversations 1/1 (allocated/max allocated)

     Available Bandwidth 250000 kilobits/sec

  5 minute input rate 6033000 bits/sec, 752 packets/sec

  5 minute output rate 2431000 bits/sec, 623 packets/sec

     782071494 packets input, 2240142197 bytes, 0 no buffer

     Received 8562996 broadcasts, 0 runts, 0 giants, 31 throttles

     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

     0 watchdog, 2248415 multicast, 0 pause input

     0 input packets with dribble condition detected

     733199563 packets output, 2585060426 bytes, 0 underruns

     9 output errors, 0 collisions, 6 interface resets

     0 babbles, 0 late collision, 0 deferred

     9 lost carrier, 0 no carrier, 0 pause output

     0 output buffer failures, 0 output buffers swapped out

Cisco3750-a#sho int gig1/0/23

GigabitEthernet1/0/23 is up, line protocol is up (connected)

  Hardware is Gigabit Ethernet, address is 0022.bda2.b717 (bia 0022.bda2.b717)

  MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,

     reliability 255/255, txload 2/255, 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 00:00:00, output 00:00:00, output hang never

  Last clearing of "show interface" counters never

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 19

  Queueing strategy: fifo

  Output queue: 0/40 (size/max)

  5 minute input rate 2931000 bits/sec, 879 packets/sec

  5 minute output rate 10467000 bits/sec, 1156 packets/sec

     159496831 packets input, 60740883950 bytes, 0 no buffer

     Received 750524 broadcasts (427195 multicasts)

     0 runts, 0 giants, 0 throttles

     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

     0 watchdog, 427195 multicast, 0 pause input

     0 input packets with dribble condition detected

     211681195 packets output, 200393435881 bytes, 0 underruns

     0 output errors, 0 collisions, 1 interface resets

     0 unknown protocol drops

     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

Highlighted
Beginner

Re: Wacky Routing issue with VLAN

Just one little thing - use the button on the front of your stack of 3750s to confirm how they are numbered in their stack 1, 2, 3.

Maybe G1/0/23 isn't actually the port you think it is.

Highlighted
mbj Beginner
Beginner

Wacky Routing issue with VLAN

So I did some layer 1 troubleshooting.....

I of course assumed that logically the Router was plugged directly into our core switch....oops. It turns out the last network engineer plugged the router into a Netgear switch that plugged into the router.

So after fixing this issue...it has been resolved. Wow I cannot believe I didnt look at the wiring.

Highlighted
Hall of Fame Master

Wacky Routing issue with VLAN

Aaron

Thanks for posting back with the update. I am very glad that you have solved the issue and have shared the solution with us.

If anyone needs it, this is a very good reminder that in troubleshooting what might appear to be a layer 3 routing problem that we need to be very careful to verify layers 1 and 2.

Now perhaps you can mark this question as answered?

HTH

Rick

HTH

Rick

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