R2511-HP MSR Router Series Interface Configuration Guide(V5)

[Router] interface cellular-ethernet 0/0

[Router-Cellular-Ethernet0/0] ip address cellular-allocated

# Enable circular DCC (C-DCC) on interface Cellular-Ethernet 0/0.

[Router-Cellular-Ethernet0/0] dialer enable-circular

# Associate interface Cellular-Ethernet 0/0 with dialer access group 1.

[Router-Cellular-Ethernet0/0] dialer-group 1

# Configure a dial string for calling a remote end.

[Router-Cellular-Ethernet0/0] dialer number *99#

# Enable outbound NAT on interface Cellular-Ethernet 0/0.

[Router-Cellular-Ethernet0/0] nat outbound

[Router-Cellular-Ethernet0/0] quit

# Configure a default route to interface Cellular-Ethernet 0/0, and enable dynamic domain name

resolution.

[Router] ip route-static 0.0.0.0 0.0.0.0 Cellular-Ethernet0/0

[Router] dns resolve

[Router] dns proxy enable

RSSI-based interface backup configuration example

Network requirements

As shown in Figure 4, the router provides two 3G modem modules. They are managed in Cellular 1/0

(the master interface) view and Cellular 2/0 (the subordinate interface) view.

Configure the signal strength threshold as –90 dBm and the delay time as 60 minutes so that when the

signal strength is below –90 dBm on the master interface, traffic is switched to the subordinate interface.

When the signal strength is over –90 dBm on the master interface, traffic is switched back to the master

interface.

Specify the destination address for NQA operation as 8.8.8.8, and set the number of consecutive probe

failures to five so that when the number of consecutive probe failures exceeds five (included), the state of

the track entry is changed to negative.

Figure 4 Network diagram

Configuration procedure

# Configure an NQA operation with the administrator name z and operation tag i to check the

connectivity of the link on the master interface.

<Router> system-view

[Router] nqa entry z i

[Router-nqa-z-i] type icmp-echo

[Router-nqa-z-i-icmp-echo] destination ip 8.8.8.8

[Router-nqa-z-i-icmp-echo] frequency 4000

[Router-nqa-z-i-icmp-echo] reaction 1 checked-element probe-fail threshold-type

consecutive 5 action-type trigger-only