1.设置静态路由
RouterA(config)#ip route 172.16.50.0 255.255.255.0 172.16.60.2
RouterA(config)#ip route 172.16.60.2 255.255.255.255 bri0
2.设置Interesting Traffic
804A(config)#dialer-list 1 protocol ip permit
804A(config)#int bri0
804A(config-if)#dialer-group 1
3.配置Dialer信息
804A#config t
804A(config)#int bri0
804A(config-if)#ip address 172.16.60.1 255.255.255.0
804A(config-if)#no shut
804A(config-if)#encapsulation ppp
804A(config-if)#dialer-group 1
804A(config-if)#dialer-string 8350661
或者用804A(config-if)#dialer map ip 172.16.60.2 name 804B 8350661
代替dialer-string
sh run
804B#sh run
Building configuration...
Current configuration:
!
version 12.0
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname 804B
!
ip subnet-zero
!
isdn switch-type basic-ni
!
interface Ethernet0
ip address 172.16.50.10 255.255.255.0
no ip directed-broadcast
!
interface BRI0
ip address 172.16.60.2 255.255.255.0
no ip directed-broadcast
encapsulation ppp
dialer idle-timeout 300
dialer string 8358661
dialer load-threshold 2 either
dialer-group 1
isdn switch-type basic-ni
isdn spid1 0835866201 8358662
isdn spid2 0835866401 8358664
hold-queue 75 in
!
ip classless
ip route 172.16.30.0 255.255.255.0 172.16.60.1
ip route 172.16.60.1 255.255.255.255 BRI0
!
dialer-list 1 protocol ip permit
!
可选参数
The dialer load-threshold command tells the BRI interface when to
bring up the second B channel. The option is from 1?255, where 255 tells the
BRI to bring up the second B channel only when the first channel is 100 percent
loaded. The second option for that command is in, out, or either. This
calculates the actual load on the interface on outbound traffic, inbound traffic,
or on the two combined. The default is outbound.
The dialer idle-timeout command specifies the number of seconds
before a call is disconnected after the last interesting traffic is sent. The
default is 120 seconds.
RouterA(config-if)#dialer load-threshold 125 either
RouterA(config-if)#dialer idle-timeout 180
The dialer load-threshold 125 tells the BRI interface to bring up the
second B channel if either the inbound or outbound traffic load is 50 percent.
The dialer idle-timeout 180 changes the default disconnect time from
120 to 180 seconds.
Multilink PPP (MP) allows load balancing between the two B channels in
a BRI. It is non-vendor specific, and provides packet fragmentation and reassembly,
sequencing, and load calculating. Cisco’s MP is based on RFC 1990.
The configuration would then look like this:
RouterA(config-if)#dialer load-threshold 125 either
RouterA(config-if)#dialer idle-timeout 180
RouterA(config-if)#ppp multilink
Not a tough configuration, but you want to use it nonetheless. This command
will fragment packets and send them over both lines, which provides
a load balancing effect of the data packet. You can verify the multilink is
working with the show ppp multilink command.
2个B信道
如果要同时激活2条B信道，可以使用
dialer load-threshold 1
也就是说把流量负载的值设到最小就可以了