Unable to dial fault resolution due to ungrounded router

Failure phenomenon

The author has once configured an AM module. There was a strange problem. When configured, no modem dial tone is dialed. Only the sound of the telephone. And the sound indicator is not lit. When the author unplug the phone line on the module. The indicator light is on.

Configuration

620#sh Run

Building configuration ...

Current configuration:866 bytes

!

Version 12.2

Service Timestamps Debug Uptime

Service Timestamps Jog uptime

No service password-encryption

!

hostname2620

Enable Secret 5 $1$PURF$9XGOG.ZYXKAWI9NLJLHHR1

Usernameuser Password 0 Cisco

IP Subnet-zero

!

!

No IP domain-lookup

!

!

!

!

Interface fastethernet0/0

IP address 136.0.0.254255.255.0.0

Duplex Auto

Speed auto

!

Interface Group-async1

IP unnumbered fastethernet0/0

Encapsulation PPP

Async Default Routing

Async Mode Interactive

Peer default IP address pool lab

PPP Authentication CHAP

Group-range 33 48

!

!

IP classless

No IP HTTP Server

IP PIM bidir-enable

!

!

Line con 0

Password Cisco

Line 33 48

Login Local

Modem InOut

Autocommand PPP

Transport input All

AutoSelect PPP

StopBits 1

FlowControl Hardware

Line aux0

Line vty 0 4

Password Cisco

Login

!

No Scheduler Allocate

End

Diagnostics process

The author carefully examines the configuration file and finds that the IP pool is missing, plus the IP local pool lab (start IP addr) (stop IP addr) has no effect. Later, the author thought of the use of dial-up analog signals, and grounding has a great relationship. No automatic response: Most of the grounding problem. So directly to the router grounding screws, with a wire to anti-static floor under the iron pillar, the problem solved.

Excluding experience

Router Standard grounding method is in the laying of the power cord when placed a ground wire, and then the shell of the router to the ground up on the good?, the author estimates that the original network system for the manufacturers to use the power line ignored the ground, otherwise it will not appear such a ship. If there is a ground wire when the router is plugged in, there is no need for us to ground again.