06-29-2010 01:40 PM - edited 03-06-2019 11:49 AM
I am trying to setup trunk between two 3550s. I configured the trunk one each switch as usual but the port always show interface is down and notconnected (The cable is good).
The IOS version is 12.1(22)EA1a.
interface FastEthernet0/24
switchport trunk encapsulation dot1q
switchport mode trunk
Switch#sh int f0/24
FastEthernet0/24 is down, line protocol is down (notconnect)
Hardware is Fast Ethernet, address is 000e.84f6.3618 (bia 000e.84f6.3618)
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Auto-duplex, Auto-speed, media type is 100BaseTX
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 00:10:55, 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
I was thinking on trunk encapsulation and tried both dot1q and isl were all not working. I even removed the trunk setting and put them on same VLAN, the ports still show down and notconnected. This is weird to me. When I connected any one of 3550 with other device like ASA5520 with trunk setting, it works fine.
Is there special setting for configuring trunk between 3550s?
Thank you in advance.
06-29-2010 01:49 PM
Here is a stupid question but is sometimes overlooked, are you using a crossover cable?
06-29-2010 02:06 PM
Of cause not crossed cable as I mentioned the cable is correct otherwise I won't ask this stupid question
06-29-2010 02:31 PM
Switch <-> Switch you need a Xover cable unless the switches have Auto-MDIX support (which I don't recall being supported on
3550s)
Switch <-> ASA a regular cable will work.
Do yourself a favor and get a Xover cable.
Regards,
Edison.
06-30-2010 10:59 AM
OMG, never pay attention on that. Auto-adapt has been implemented to most of ethernet cards in last decade.
Anyway, let me try cross cable thgouh. Thanks a lot.
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