我正在尝试配置几个 Cisco 1941 路由。它们都是相同的路由器。每个路由器都有一个 HWIC-1T（智能串行接口）和一个 HWIC-3G-HSPA 3G 接口。这些路由器将被发送到远程站点。我们可以连接到其中一个站点，但如果远程站点 A 发生故障，我们将失去与远程站点 B 的连接。
HWIC-1T 是使用帧中继连接两个远程站点的主要 WAN 接口
我们希望 HWIC-3G-HSPA 可用于从总部到远程站点 B 的直接连接，并且当帧中继发生故障时（经常发生），HWIC-3G-HSPA 可用于远程站点之间的通信。
我最初尝试使用 EIGRP 进行动态路由，但在我的笔记本电脑实验室设置中 - 1941 - 1941 - 笔记本电脑，我无法获得端到端连接。后来我决定使用静态路由，并获得了端到端连接，但仅通过帧中继，而不是 HWIC-3G-HSPA。
远程站点 A 的净化运行配置：
version 15.1
service tcp-keepalives-in
service tcp-keepalives-out
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
service udp-small-servers
service tcp-small-servers
!
hostname remoteA
!
boot-start-marker
boot-end-marker
!
!
logging buffered 51200 warnings
enable secret 5 censored
!
no aaa new-model
clock timezone wst 8 0
!
no ipv6 cef
ip source-route
ip cef
!
ip domain name yourdomain.com
multilink bundle-name authenticated
!
chat-script gsm "" "ATDT*98*1#" TIMEOUT 30 "CONNECT"
!
username admin privilege 15 secret 5 censored
!
controller Cellular 0/1
!
interface Embedded-Service-Engine0/0
no ip address
shutdown
!
interface GigabitEthernet0/0
ip address 192.168.2.5 255.255.255.0
duplex auto
speed auto
!
interface GigabitEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0/0
ip address 10.1.1.2 255.255.255.252
encapsulation frame-relay
cdp enable
frame-relay interface-dlci 16
frame-relay lmi-type ansi
!
interface Cellular0/1/0
ip address negotiated
encapsulation ppp
dialer in-band
dialer idle-timeout 2147483
dialer string gsm
dialer-group 1
async mode interactive
ppp chap hostname censored
ppp chap password 7 censored
cdp enable
!
interface Cellular0/1/1
no ip address
encapsulation ppp
!
interface Dialer0
no ip address
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
ip route 0.0.0.0 0.0.0.0 Serial0/0/0 210 permanent
ip route 0.0.0.0 0.0.0.0 Cellular0/1/0 220 permanent
ip route 172.31.2.0 255.255.255.0 Cellular0/1/0 permanent
ip route 192.168.3.0 255.255.255.0 10.1.1.1 permanent
ip route 192.168.3.0 255.255.255.0 Cellular0/1/0 210 permanent
!
access-list 1 permit any
dialer-list 1 protocol ip list 1
!
control-plane
!
line con 0
logging synchronous
login local
line aux 0
line 2
no activation-character
no exec
transport preferred none
transport input all
transport output pad telnet rlogin lapb-ta mop udptn v120 ssh
stopbits 1
line 0/1/0
exec-timeout 0 0
script dialer gsm
login
modem InOut
no exec
transport input all
rxspeed 7200000
txspeed 5760000
line 0/1/1
no exec
rxspeed 7200000
txspeed 5760000
line vty 0 4
access-class 23 in
privilege level 15
password 7 censored
login local
transport input all
line vty 5 15
access-class 23 in
privilege level 15
password 7 censored
login local
transport input all
line vty 16 1370
password 7 censored
login
transport input all
!
scheduler allocate 20000 1000
end
远程站点 B 的净化运行配置：
version 15.1
service tcp-keepalives-in
service tcp-keepalives-out
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
service udp-small-servers
service tcp-small-servers
!
hostname remoteB
!
boot-start-marker
boot-end-marker
!
logging buffered 51200 warnings
enable secret 5 censored
!
no aaa new-model
clock timezone wst 8 0
!
no ipv6 cef
ip source-route
ip cef
!
no ip domain lookup
ip domain name yourdomain.com
multilink bundle-name authenticated
!
chat-script gsm "" "ATDT*98*1#" TIMEOUT 30 "CONNECT"
username admin privilege 15 secret 5 censored
!
controller Cellular 0/1
!
interface Embedded-Service-Engine0/0
no ip address
shutdown
!
interface GigabitEthernet0/0
ip address 192.168.3.1 255.255.255.0
duplex auto
speed auto
!
interface GigabitEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0/0
ip address 10.1.1.1 255.255.255.252
encapsulation frame-relay
clock rate 2000000
cdp enable
frame-relay interface-dlci 16
frame-relay lmi-type ansi
frame-relay intf-type dce
!
interface Cellular0/1/0
ip address negotiated
encapsulation ppp
dialer in-band
dialer idle-timeout 2147483
dialer string gsm
dialer-group 1
async mode interactive
ppp chap hostname censored
ppp chap password 7 censored
ppp ipcp dns request
cdp enable
!
interface Cellular0/1/1
no ip address
encapsulation ppp
!
interface Dialer0
no ip address
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
ip route 0.0.0.0 0.0.0.0 Serial0/0/0 210 permanent
ip route 0.0.0.0 0.0.0.0 Cellular0/1/0 220 permanent
ip route 172.31.2.0 255.255.255.0 Cellular0/1/0 permanent
ip route 192.168.2.0 255.255.255.0 10.1.1.2 permanent
ip route 192.168.2.0 255.255.255.0 Cellular0/1/0 210 permanent
!
kron occurrence PING in 1 recurring
policy-list ICMP
!
access-list 1 permit any
dialer-list 1 protocol ip list 1
!
control-plane
!
line con 0
logging synchronous
login local
line aux 0
line 2
no activation-character
no exec
transport preferred none
transport input all
transport output pad telnet rlogin lapb-ta mop udptn v120 ssh
stopbits 1
line 0/1/0
exec-timeout 0 0
script dialer gsm
login
modem InOut
no exec
transport input all
rxspeed 7200000
txspeed 5760000
line 0/1/1
no exec
rxspeed 7200000
txspeed 5760000
line vty 0 4
access-class 23 in
privilege level 15
password 7 censored
login
transport input all
line vty 5 15
access-class 23 in
privilege level 15
password 7 censored
login
transport input all
line vty 16 1370
password 7 censored
login
transport input all
!
scheduler allocate 20000 1000
end
我遇到的最后一个问题是 3G 接口在几分钟不活动后就会关闭。我尝试使用 kron 每分钟 ping 一次本地 HWIC-3G-HSPA 接口 (cellular 0/1/0)，但没有成功。手动 ping 分配给 ce0/1/0 的 IP（由电信公司分配）确实会启动接口。
有任何想法吗？
谢谢
答案1
您可以建立一个虚假的 GRE 隧道来发送数据包，以维持接口正常运行。
router(config)# int tun0
router(config-if)# ip unnunbered <lan interface>
router(config-if)# tunnel mode gre
router(config-if)# tunnel source <lan interface>
router(config-if)# tunnel dest <default 3G gateway>
隧道目的地也可以是任何 IP，只要您有通过 3G 的路由。隧道将保持关闭状态（因为不会回复保持活动消息），但发送的保持活动将强制 3G 接口保持开启状态。