We have a Cisco Router Cisco 1900, and our
ISP told us that our config (below) has the wrong duplex setting. They want us
to change it to 100 FULL.
1. What is the command to change the
duplex to FULL (without restarting the router).
2. What if the link goes down, how
do I revert back to the old settings (AUTO)?
interface GigabitEthernet0/0
description Internet via $ETH-WAN$$FW_OUTSIDE$
ip address 209.xx.xx.xx 255.255.255.252
ip access-group 101 in
no ip redirects
no ip proxy-arp
ip verify unicast reverse-path
ip flow ingress
duplex auto
speed 100
no mop enabled
interface GigabitEthernet0/0
spped 100
duplex full
sh int gi 0/0 will show the current settings .
show int --> shows half duplex..
did u apply the commands
regarding question number 2 ... no need to restart .
just change the duplex to auto ( duplex auto)
or
int gi 0/0
shut
no shut.
The other end could also just not be
Cisco 1900 sereis router, sometimes disparate hardware requires that you force the GB connection
to Full.
The standard is to set 1Gbps
connections to auto, but when it first came out we often had to force it to get
it to work with some hardware.
Sometimes when the duplex
negotiation fails it will fall-back to half-duplex. Therefore it's not correct to say that the
other end is definitely set to half.
Negotiation could fail for a number of reasons, including manually
specifying the speed.
The main reason ISPs specify manual
speed and duplex settings is because they want to mitigate any chance of
auto-negotiation failure which would result in half-duplex operation and
therefore reduce support incidents.
