[svc]gns3模拟器及探讨几个bgp问题

模拟器

链接：https://pan.baidu.com/s/1geMcmND 密码：7iir

gns0.8.6的版本好用

思科的这个iso好用: c3660-js2-mz.124-21a.bin C2691-AD.BIN(这个也很ok,但是这两个支持的hash算法较少)

ctrl+shit+6 停止命令

R1(config)#crypto isakmp policy 10
R1(config-isakmp)#hash ?
md5 Message Digest 5
sha Secure Hash Standard


cisco ios命名参考

c7200-adventerprisek9-mz.151-4.M2.bin #做证书实验用这个

R1(config)#crypto isakmp policy 10
R1(config-isakmp)#hash ?
md5 Message Digest 5
sha Secure Hash Standard
sha256 Secure Hash Standard 2 (256 bit)
sha384 Secure Hash Standard 2 (384 bit)
sha512 Secure Hash Standard 2 (512 bit)

- 思科ios冷知识1: RAM：随机访问存储器，相当于计算机的内存
2：ROM：只读存储器，在ROM中驻留了用于启动和维护路由器的一些微代码
3：FLASH: 闪存，相当于计算机的硬盘，存储了IOS文件映像
4：NVRAM: 主要用于存储启动配置文件( Non-Volatile[挥发的] Random Access Memory)
思科路由器不具备存储历史错误记录的能力，只能通过debug进行即时排错。

探讨bgp几个问题

防止环路:

as间 as-path

as内 水平分割

full mesh

更新源的问题

同步问题

ibgp水平分割

• 基础ip配置

R1conf t
int lo0
ip add 1.1.1.1 255.255.255.255
int f0/0
ip add 12.1.1.1 255.255.255.0
no shuR2conf t
int lo0
ip add 2.2.2.2 255.255.255.255
int f0/0
ip add 12.1.1.2 255.255.255.0
no shu
int f0/1
ip add 23.1.1.2 255.255.255.0
no shuR3conf t
int l0
ip add 3.3.3.3 255.255.255.255
int f0/0
ip add 34.1.1.3 255.255.255.0
no shu
int f0/1
ip add 23.1.1.3 255.255.255.0
no shuR4conf t
int l0
ip add 4.4.4.4 255.255.255.255
int f0/0
ip add 34.1.1.4 255.255.255.0
no shu


• bgp建立full mesh

R1#s run | s bgp
router bgp 123
no synchronization
bgp router-id 1.1.1.1
bgp log-neighbor-changes
network 1.1.1.1 mask 255.255.255.255
neighbor 2.2.2.2 remote-as 123
neighbor 2.2.2.2 update-source Loopback0
neighbor 3.3.3.3 remote-as 123
neighbor 3.3.3.3 update-source Loopback0
no auto-summaryR2#s run | s bgp
router bgp 123
bgp router-id 2.2.2.2
bgp log-neighbor-changes
neighbor 1.1.1.1 remote-as 123
neighbor 1.1.1.1 update-source Loopback0
neighbor 3.3.3.3 remote-as 123
neighbor 3.3.3.3 update-source Loopback0R3#s run | s bgp
router bgp 123
bgp router-id 3.3.3.3
bgp log-neighbor-changes
neighbor 1.1.1.1 remote-as 123
neighbor 1.1.1.1 update-source Loopback0
neighbor 1.1.1.1 next-hop-self
neighbor 2.2.2.2 remote-as 123
neighbor 2.2.2.2 update-source Loopback0
neighbor 2.2.2.2 next-hop-self
neighbor 34.1.1.4 remote-as 4R4#s run | s bgp
router bgp 4
bgp router-id 4.4.4.4
bgp log-neighbor-changes
network 4.4.4.4 mask 255.255.255.255
neighbor 34.1.1.3 remote-as 123