
6-5
Cisco 1800 Series Integrated Services Routers (Fixed) Hardware Installation Guide
OL-6425-03
Chapter 6 Troubleshooting
Reading Port and Connection LEDs
Table 6-2
Port and Connection Indicators on Cisco 1800 Series Fixed-Configuration Routers
LED Indicator
State
Meaning
Corrective Action
FE
x
Off
The Ethernet interface next
to the LED is not receiving
packets.
Ethernet is not active or is not connected. Check
Ethernet connections and make corrections as
necessary.
Router is not configured properly. Check
configuration and make corrections as necessary.
Solid or blinking
green
The Ethernet interface next
to the LED is receiving
packets.
Normal indication. No action is required.
CD
1
(on Cisco 1801,
Cisco 1802, and
Cisco 1803 routers)
Off
No DSL connection is
established.
Normal indication unless a DSL connection is
required.
If a DSL connection is expected, check DSL
connections and make corrections as necessary.
Router is not configured properly. Check
configuration and make corrections as necessary.
Green
DSL connection is
established.
Normal indication. No action is required.
CD
1
(on Cisco 1811
routers)
Off
No analog modem
connection is established.
Normal indication unless a modem connection is
required.
If a modem connection is expected, check modem
connections and make corrections as necessary.
Router is not configured properly. Check
configuration and make corrections as necessary.
Green
Analog modem connection is
established.
Normal indication. No action is required.
LPBK
2
Off
DSL interface is operating in
normal mode.
Normal indication. No action is required.
Green
DSL interface is in loopback
mode.
—
LINK
3
Off
No ISDN BRI S/T
connection is established.
Normal indication unless an ISDN BRI connection
is required.
If an ISDN BRI connection is expected, check
ISDN BRI S/T connections and make corrections
as necessary.
Router is not configured properly. Check
configuration and make corrections as necessary.
Green
An ISDN BRI S/T D channel
connection is established.
Normal indication. No action is required.
B1
3
Blinking green
Activity on the first B
channel.
Indication is for information only.
B2
3
Blinking green
Activity on the second B
channel.
Indication is for information only.