Here's what it says in the Cisco manuals from their website:
RTD-1-LINK_FLAP [chars] link down/up [dec] times per min
Explanation This message indicates that an excessive number of link
down-up events has been noticed on this interface: [chars] is the
interface, and [dec] is the number of times the link goes up and down.
This might be the result of reconfiguring the port, or it might
indicate a faulty device at the other end of the connection.
Action If someone is reconfiguring the interface or device at the
other side of the interface, ignore this message. However, if no one
is manipulating the interface or device at the other end of the
interface, it is likely that the Ethernet transceiver at one end of
the link is faulty and should be replaced.
I'm having that problem on a couple of connections in my office. I
think it's a bad cable or bad connections in my case, since the
equipment works fine when connected elsewhere. I am not able to use
power over ethernet for my Cisco IP phones on that connection either.
I'm trying locking down the ports at 10 Mbps and half duplex to see if
Has anyone seen this before?
Syslog message generated from device 10.18.128.38: May 01 09:43:36
May 1 09:39:59: %RTD-1-LINK_FLAP: FastEthernet0/7 link down/up 5 times
We have seen this happening starting a couple of weeks ago and only on
the 3500XL switches. At first we thought this was related to wireless
users and AP ports only. We were wrong. We see this error occurring on
a lot of the 3500s now.
Thanks in Advance.
11. port flapping
13. e3 line flapping