author:leadlife
data:2022/9/5
mains:www.leadlifesec.com
Enhanced interior Gateway Routing Protocol
EIGRP 基于距离矢量路由协议
EIGRP 特点
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高级距离矢量协议——具有距离矢量性和链路状态协议特征
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无类路由协议——可划分子网,可聚合子网路由(有类路由协议——RIP 无掩码)
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支持 VLSM 与不连续子网
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100%无环路——
DUAL算法
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快速收敛——路由条目不过期,拥有备份路由
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触发更新
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低路由更新信息开销
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配置简单
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支持多种路网络协议(IP,ipx...)
0x01 EIGRP 的 Metric
我们之所以称 EIGRP 为增强型的内部网关协议,原因在于它是个强大的路由功能
EIGRP 具有 5 种选择路由的方式 而 RIP 的动态路由协议,只根据 跳数来决定它的 metric 1:Bandwidth 宽带 2:delay 延迟 3:Reliability 可用性 4:loading 加载性,负载 5:MTU 不知道干啥的
EIGRP 路由表参考
直连 C 、静态 S、RIP R、EIGRP D
0x03 EIGRP 核心算法 DUAL 算法
利于计算最佳五环路径和备用路径
特点如下:
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无环路拓扑
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可立即使用的无环备份路径
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快速收敛
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低宽带利用率
了解 DUAL 算法中的术语:
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后继路由器 => 即根据 EIGRP 算法选出来的最佳路线的下一跳路由器,叫做后继路由器
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可行距离(FD) => 本地到达目标的距离
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可行后继路由器 => 备份的下一跳最佳路由器
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通告距离(AD) => 前往目的,的距离
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可行条件 (FC)
0x04 EIGRP 基本配置
EIGRP命令格式如下
Router(config)# router eigrp autonomous-system
# EIGRP 将 autonomous-system 参数称为 "自治系统" 编号
Router(config-router)# network network-number [wildcard-mask]
EIGRP 完整配置
eigrp 基本配置与 OSPF 相似,区别在于 eigrp 使用 autonomous-system 编号区分,而 ospf 以 area
R3(config)#router eigrp 100 * auto 值
R3(config-router)#network 192.168.2.0 * 宣告直连
R3(config-router)#network 20.1.1.0
*Mar 1 00:10:58.051: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 20.1.1.1 (FastEthernet0/1) is up: new adjacency * 响应信息
R3#show ip route
Gateway of last resort is not set
20.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 20.1.1.0/24 is directly connected, FastEthernet0/1
D 20.0.0.0/8 is a summary, 00:00:07, Null0
D 10.0.0.0/8 [90/307200] via 20.1.1.1, 00:00:05, FastEthernet0/1
D 192.168.1.0/24 [90/435200] via 20.1.1.1, 00:00:05, FastEthernet0/1
C 192.168.2.0/24 is directly connected, Loopback0
R3#ping 192.168.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 24/38/52 ms
show eigrp 信息命令
查看 EIGRP 邻居路由信息
R3#show ip eigrp neighbors
IP-EIGRP neighbors for process 100
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
0 20.1.1.1 Fa0/1 12 00:03:02 39 234 0 10
EIGRP 路由调试 defbug
R1#debug eigrp ?
fsm EIGRP Dual Finite State Machine events/actions
neighbors EIGRP neighbors
nsf EIGRP Non-Stop Forwarding events/actions
packets EIGRP packets
transmit EIGRP transmission events
R1#debug ip eigrp
IP-EIGRP Route Events debugging is on
R1(config)#interface fastEthernet 0/0
R1(config-if)#no shutdown
*Mar 1 00:20:43.419: IP-EIGRP(Default-IP-Routing-Table:100): route installed for 10.0.0.0 (Summary)
*Mar 1 00:20:43.467: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.1.1.2 (FastEthernet0/0) is up: new adjacency
R1(config-if)#ex
*Mar 1 00:20:43.483: IP-EIGRP(Default-IP-Routing-Table:100): Processing incoming UPDATE packet
*Mar 1 00:20:43.483: IP-EIGRP(Default-IP-Routing-Table:100): 192.168.1.0/24 - do advertise out FastEthernet0/0
*Mar 1 00:20:43.487: IP-EIGRP(Default-IP-Routing-Table:100): Int 192.168.1.0/24 metric 128256 - 256 128000
*Mar 1 00:20:43.487: IP-EIGRP(Default-IP-Routing-Table:100): 10.1.1.0/24 - do advertise out FastEthernet0/0
*Mar 1 00:20:43.487: IP-EIGRP(Default-IP-Routing-Table:100): 10.0.0.0/8 - poison advertise out FastEthernet0/0
R1(config-if)#
*Mar 1 00:20:45.375: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed state to up
*Mar 1 00:20:45.499: IP-EIGRP(Default-IP-Routing-Table:100): Processing incoming UPDATE packet
*Mar 1 00:20:45.499: IP-EIGRP(Default-IP-Routing-Table:100): Int 20.0.0.0/8 M 307200 - 256000 51200 SM 281600 - 256000 25600
*Mar 1 00:20:45.503: IP-EIGRP(Default-IP-Routing-Table:100): route installed for 20.0.0.0 ()
*Mar 1 00:20:45.503: IP-EIGRP(Default-IP-Routing-Table:100): Int 192.168.2.0/24 M 435200 - 256000 179200 SM 409600 - 256000 153600
*Mar 1 00:20:45.503: IP-EIGRP(Default-IP-Routing-Table:100): route installed for 192.168.2.0 ()
*Mar 1 00:20:45.511: IP-EIGRP(Default-IP-Routing-Table:100): 192.168.1.0/24 - do advertise out FastEthernet0/0
*Mar 1 00:20:45.511: IP-EIGRP(Default-IP-Routing-Table:100): Int 192.168.1.0/24 metric 128256 - 256 128000
*Mar 1 00:20:45.511: IP-EIGRP(Default-IP-Routing-Table:100): 10.1.1.0/24 - do advertise out FastEthernet0/0
*Mar 1 00:20:45.511: IP-EIGRP(Default-IP-Routing-Table:100): 10.0.0.0/8 - poison advertise out FastEthernet0/0
*Mar 1 00:20:45.531: IP-EIGRP(Default-IP-Routing-Table:100): Processing incoming UPDATE packet
*Mar 1 00:20:45.531: IP-EIGRP(Default-IP-Routing-Table:100): Int 20.0.0.0/8 M 307200 - 256000 51200 SM 281600 - 256000 25600
*Mar 1 00:20:45.535: IP-EIGRP(Default-IP-Routing-Table:100): Int 192.168.2.0/24 M 435200 - 256000 179200 SM 409600 - 256000 153600
*Mar 1 00:20:45.571: IP-EIGRP(Default-IP-Routing-Table:100): Processing incoming UPDATE packet
*Mar 1 00:20:45.571: IP-EIGRP(Default-IP-Routing-Table:100): Int 192.168.1.0/24 M 4294967295 - 256000 4294967295 SM 4294967295 - 256000 4294967295
*Mar 1 00:20:45.751: IP-EIGRP(Default-IP-Routing-Table:100): 192.168.1.0/24 - do advertise out FastEthernet0/0
*Mar 1 00:20:45.751: IP-EIGRP(Default-IP-Routing-Table:100): Int 192.168.1.0/24 metric 128256 - 256 128000
*Mar 1 00:20:45.751: IP-EIGRP(Default-IP-Routing-Table:100): 10.1.1.0/24 - do advertise out FastEthernet0/0
*Mar 1 00:20:45.755: IP-EIGRP(Default-IP-Routing-Table:100): 10.0.0.0/8 - poison advertise out FastEthernet0/0
*Mar 1 00:20:46.375: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up
0x05 EIGRP 自动汇总理论
同样,动态路由,会自主的学习 IP 地址,观察网络中的变化,`高于 RIP 协议的 EIGRP 拥有
强大的功能,当学习到的路由来自同一个网段时,``EIGRP 为了防止路由表过于臃肿
,从而会
开启自动汇总功能
专业术语中前者RIP 的算法叫做 明细算法
,当连接主机 连续DOWN或 UP 时,路由会自动启动
vai 算法,从而重复这个过程,消耗CPU的资源
汇总地址 EIGRP
D 10.0.0.0/8 is a summary, 00:10:29, Null0
0x06 EIGRP 路由排错思维
总结
EIGRP 自动开启负载均衡 [若 megic 值相等,那么可以多条传输数据]
EIGRP 不等价负载均衡
通常在负载均衡中,多条链路一起传输流量,若 megic 值不一样,则 EIGRP 只使用一条,
另一条做 后继路由,为 RIGRP 配置 variance 值可启用不等价负载均衡