Router#debug seri int Serial network interface debugging is on Router# -5-UPDOWN: Line protocol on Interface Serial0, changed state to down Serial0: attempting to restart HD(0): Deasserting DTR and RTS HD(0): Reset from 0x30286DA HD(0): Asserting DTR...

CISCO 2511 router interface seri0 problemRouter#debug seri int Serial network interface debugging is on Router# -5-UPDOWN: Line protocol on Interface Serial0, changed state to down Serial0: attempting to restart HD(0): Deasserting DTR and RTS HD(0): ...

00:55:19338933932: %SYS-3-CPUHOG: Task ran for 2256 msec (17/10), process = ARP Input, PC = 803A9048. -Traceback= 803A904C 80421C98 803BCA7C