Similar to issue https://github.com/FRRouting/frr/issues/4876, ldpd randomly sta…rts running at 100% CPU utilisation.
We are running FRR v7.4-dev with all commits up until the 20th of January 2020, I observe no new commits to ldpd since then.
We do not have any dynamic interfaces, only vlan sub interfaces off a single ethernet interface.
[x] Did you check if this is a duplicate issue?
[x] Did you test it on the latest FRRouting/frr master branch?
![image](https://user-images.githubusercontent.com/1456100/73270984-75a22480-41e8-11ea-9e47-9a8f7c63edd6.png)
Repeated content when running 'strace -fF -p 962':
```
strace: deprecated option -F ignored
strace: Process 962 attached
getrusage(RUSAGE_THREAD, {ru_utime={tv_sec=16693, tv_usec=251666}, ru_stime={tv_sec=22598, tv_usec=508843}, ...}) = 0
sendmsg(17, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\0\1\0\34)O\26-\0\0\0\1\0\22\0\21X\365\3\0\0\n\200\0\0\20\0\0\0\0\0\0", iov_len=32}], msg_iovlen=
1, msg_controllen=0, msg_flags=0}, 0) = -1 EPIPE (Broken pipe)
--- SIGPIPE {si_signo=SIGPIPE, si_code=SI_USER, si_pid=962, si_uid=113} ---
write(8, "\1", 1) = 1
getrusage(RUSAGE_THREAD, {ru_utime={tv_sec=16693, tv_usec=251666}, ru_stime={tv_sec=22598, tv_usec=508978}, ...}) = 0
poll([{fd=3, events=POLLIN}, {fd=9, events=POLLIN}, {fd=10, events=POLLIN}, {fd=11, events=POLLIN}, {fd=12, events=POLLIN}, {fd=13, events=POLLIN}, {fd=16, even
ts=POLLIN}, {fd=14, events=POLLIN}, {fd=15, events=POLLIN}, {fd=17, events=POLLOUT}, {fd=7, events=POLLIN}], 11, 64) = 2 ([{fd=17, revents=POLLOUT|POLLHUP}, {fd
=7, revents=POLLIN}])
read(7, "\1", 64) = 1
read(7, 0x7fff343825d0, 64) = -1 EAGAIN (Resource temporarily unavailable)
getrusage(RUSAGE_THREAD, {ru_utime={tv_sec=16693, tv_usec=251666}, ru_stime={tv_sec=22598, tv_usec=509134}, ...}) = 0
sendmsg(17, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\0\1\0\34)O\26-\0\0\0\1\0\22\0\21X\365\3\0\0\n\200\0\0\20\0\0\0\0\0\0", iov_len=32}], msg_iovlen=
1, msg_controllen=0, msg_flags=0}, 0) = -1 EPIPE (Broken pipe)
--- SIGPIPE {si_signo=SIGPIPE, si_code=SI_USER, si_pid=962, si_uid=113} ---
write(8, "\1", 1) = 1
getrusage(RUSAGE_THREAD, {ru_utime={tv_sec=16693, tv_usec=251666}, ru_stime={tv_sec=22598, tv_usec=509280}, ...}) = 0
poll([{fd=3, events=POLLIN}, {fd=9, events=POLLIN}, {fd=10, events=POLLIN}, {fd=11, events=POLLIN}, {fd=12, events=POLLIN}, {fd=13, events=POLLIN}, {fd=16, even
ts=POLLIN}, {fd=14, events=POLLIN}, {fd=15, events=POLLIN}, {fd=17, events=POLLOUT}, {fd=7, events=POLLIN}], 11, 61) = 2 ([{fd=17, revents=POLLOUT|POLLHUP}, {fd
=7, revents=POLLIN}])
read(7, "\1", 64) = 1
read(7, 0x7fff343825d0, 64) = -1 EAGAIN (Resource temporarily unavailable)
```
Last log entry in /var/log/frr/frr.log:
`Jan 28 05:18:10 zatjnb01-rr03 ldpd[963]: tcp_new: getpeername: Transport endpoint is not connected`