下面是某路由器的部分配置信息，解释部分语句的含义。

[配置路由器信息]

C．urrent configuration：

!

hostname router1

isdn switch-type basic-net3 (1)

!

interface Ethernet0

ip address 10.0.0.1 255.255.255.0

ip nat inside (2)

!

interface bri 0

ip address negotiated (3)

ip nat outside

encapsulation PPP

PPP authentication pap callin (4)

PPP multlink (5)

dialer-group 1

dialer string 2633

PPP pap sent-username 263 password 263 (6)

ip route 0.0.0.0 0.0.0.0 bri 0

access-list 2 permit any (7)

dialer-list 1 protocol ip permit (8)

ip nat inside source list 2 interface bri 0 overload (9)

……

E．nd