been having an ongoing issue with a particular site having one of the devices line protocol flapping.
I work for a Wireless ISP and the device impacted is the back haul radio into the site. I have swapped from a 2950T to a 3550. Replaced the radio, PoE, patch lead. We have re ran the cable up the tower using shielded outdoor cable with a drain wire which has been earthed to an earthing block in the cabinet.
We have other devices on the tower not experiencing the issue. We suspect cable interference however am now at a loss to diagnose further. If anyone can suggest further troubleshooting at the switch level it would be appreciated.
Please see diagnostics so far:
Aug 28 17:37:09.563 AEST: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/7, changed state to up
Aug 28 18:22:40.563 AEST: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/7, changed state to down
Aug 28 18:22:42.567 AEST: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/7, changed state to up
Aug 28 18:45:15.923 AEST: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/7, changed state to down
Aug 28 18:45:17.927 AEST: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/7, changed state to up
QLD-SBK-3550#show int fa0/7
FastEthernet0/7 is up, line protocol is up (connected)
Hardware is Fast Ethernet, address is 000e.83f9.3287 (bia 000e.83f9.3287)
Description: RM5+RD30 to HQ Building
MTU 1546 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 2/255, rxload 4/255
Encapsulation ARPA, loopback not set
Keepalive not set
Full-duplex, 100Mb/s, media type is 10/100BaseTX
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:15, output 01:43:38, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
As it is a commercial tower there are many providers and a wide variety of device s on site so it is difficult to be 100% certain on the root cause or the offending device but in the end we relocated our radio to a different spot on the tower where there is less devices and as a result the interface is no longer flapping so I suspect that another provider has some damaged or faulty equipment that is leaking onto the tower resulting in the cable interference we were experiencing. very difficult issue to identify with no errors or real give aways.
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