最近我在调试一个网络,该网络使用一对二方式.
其中一个远端A与Internet互连,中心点与另外一个远端B通过该远端A连入Internet. 并且三点之间内部互通.
现三地之间用三台Cisco互连,能正常工作.
但是现需要备份中心点与两个远端之间的通信线路.
计划采用ISDN拨号备份.
ISDN Configuration Example - IP
-----------------------------------------------------------
Sample Configuration for C2503
C2503#wr t
######
Current configuration:
!
version 10.2
!
hostname C2503
!
enable passWord test
!
username C4000 password cisco (See username eXPlanation in the followi
ng
section.)
isdn switch-type basic-dms100
!
interface Ethernet0
ip address 172.16.10.1 255.255.255.0
!
interface Serial0
no ip address
shutdown
!
interface Serial1
no ip address
shutdown
!
interface BRI0
ip address 172.16.20.1 255.255.255.0
encapsulation ppp
bandwidth 56
dialer idle-timeout 300
dialer map ip 172.16.20.2 name C4000 speed 56 broadcast 14155551234
dialer map ip 172.16.20.2 name C4000 speed 56 broadcast 14155556789
dialer hold-queue 5
dialer load-threshold 100
dialer-group 1
isdn spid1 408555432101 5554321
isdn spid2 408555987601 5559876
ppp authentication chap
!
router igrp 1
network 172.16.0.0
!
ip route 192.168.24.0 255.255.255.0 172.16.20.2
Access-list 100 deny ip 0.0.0.0 255.255.255.255 255.255.255.255 0.0.0.
0
access-list 100 permit ip 0.0.0.0 255.255.255.255 0.0.0.0 255.255.255.
255
!
!
dialer-list 1 list 100
!
line con 0
line aux 0
line vty 0 4
password test
login
!
end
Explanation of C2503 Configuration
C2503#wr t
######
Current configuration:
!
version 10.2
!
hostname C2503
!
enable password test
!
username C4000 password cisco
The username "C4000" is the hostname of the remote router and is used
by the dialer map command below. The username is case sensitive and mu
st match the remote router's hostname exactly.
The password, which is used by the CHAP authentication process, is cas
e sensitive and must match the remote router's password exactly.
Note: To avoid confusion, the unencrypted form of the password cisco i
s shown in this sample configuration. In the actual configuration, the
password would appear in its encrypted form: 7 13061E010803, where 7
denotes the encryption type and 13061E010803 is the encrypted form of
the password cisco. When entering or making changes to the username co
mmand, always type the password in its unencrypted form and do not ent
er the encryption type (7). It is set automatically.
isdn switch-type basic-dms100
The ISDN switch type must match your carrier's equipment. If you chang
e the switch-type, you must reload the router for the new switch type
to take effect.
interface Ethernet0
ip address 172.16.10.1 255.255.255.0
interface Serial0
no ip address
shutdown
!
interface Serial1
no ip address
shutdown
!
interface BRI0
ip address 172.16.20.1 255.255.255.0
encapsulation ppp
PPP encapsulation is recommended over HDLC in order to allow the use o
f CHAP authentication.
bandwidth 56
The default bandwidth setting for a BRI interface is 64k. If you confi
gured your dialer map statements with the speed 56 option, you should
include the bandwidth statement.
Note: This command does not control the speed of your ISDN line. It se
ts the correct reference point for the BRI port's show interface stati
stics, for the dialer load-threshold command, and for IGRP/EIGRP routi
ng metrics.
dialer idle-timeout 300
This command sets the number of seconds the ISDN connection will remai
n open if no interesting traffic is being routed. The timer is reset e
ach time an interesting packet is forwarded.
dialer map ip 172.16.20.2 name C4000 speed 56 broadcast 14155551234
dialer map ip 172.16.20.2 name C4000 speed 56 broadcast 14155556789
The dialer map command is used with CHAP authentication to place the i
nitial call to the remote router when interesting traffic is forwarded
to the BRI interface. Once the connection is active, the dialer idle-
timeout command determines how long it will remain active. A dialer ma
p statement is required for each ISDN phone number that will be called
. Be aware though, that two dialer map statements pointing to the same
location might activate both B channels when you may only want to use
one channel.
Note: The command parameters for this example are:
172.16.20.2 = the IP address of the remote router's BRI interface. To
determine this address, type show interface bri 0 at the remote router
's console prompt.
name C4000 = the hostname of the remote router. The name is case sensi
tive and should match the name configured for the username command abo
ve.
speed 56 = sets the dialer speed to 56k for ISDN circuits that are not
64k end-to-end, and should be included in both routers' dialer map st
atements. Most installations in North America must be configured for 5
6K.
broadcast = allows the forwarding of broadcast packets. Unless broadca
st packets are specified as interesting packets by the dialer-list com
mand, they will only be forwarded when the ISDN link is active.
14155551234
14155556789 = the remote router's ISDN telephone numbers.
dialer hold-queue 5
This command allows interesting packets to be queued until the ISDN co
nnection is est
