MPLS TE基礎配置
這篇講MPLS TE的基礎配置。
MPLS的幾大組件就不重復了， 這篇註重配置關鍵點。
以下是我的實驗topology，
首先當你要使用MPLS TE的時候，骨幹網的每臺路由器都要開啟此功能。全局與接口命令如下。
全局
mpls traffic-eng tunnels
IGP進程命令
IS-IS
router isis
mpls traffic-eng router-id loopback 0
mpls traffic-eng level-2
metric-style wide //一定要開啟，因為MPLS TE計算metric的方式很復雜
OSPF
mpls traffic-eng router-id loopback0
mpls traffic-eng area 0
接口下的命令
物理接口
int f1/0
mpls traffic-eng tunnels
ip rsvp bandwidth <數值>
mpls ip // 必須得開啟，思科IOS設備不像Junos 有 family mpls family LDP 的區別，當接口收到一個帶標簽的報文 沒有此命令路由器會直接 丟棄。
貼一個R2的配置作為參考
R2#sh run | s router
router isis
mpls traffic-eng level-2
net 49.0020.0200.2002.00
is-type level-2-only
metric-style wide
log-adjacency-changes
R2#sh run | s interface
interface Loopback0
ip address 2.2.2.2 255.255.255.255
ip router isis
interface Ethernet0/0
no ip address
shutdown
duplex auto
interface GigabitEthernet0/0
ip address 23.1.1.2 255.255.255.0
duplex full
speed 1000
media-type gbic
negotiation auto
mpls traffic-eng tunnels
mpls ip
ip rsvp bandwidth 100000
interface FastEthernet1/0
ip address 12.1.1.2 255.255.255.0
ip router isis
duplex auto
speed auto
mpls traffic-eng tunnels
mpls ip
ip rsvp bandwidth 30000
interface FastEthernet1/1
ip address 24.1.1.2 255.255.255.0
ip router isis
duplex auto
speed auto
mpls traffic-eng tunnels
mpls ip
ip rsvp bandwidth 30000
interface FastEthernet2/0
ip address 25.1.1.2 255.255.255.0
ip router isis
duplex auto
speed auto
mpls traffic-eng tunnels
mpls ip
ip rsvp bandwidth 30000
接下來就是配置tunnel 既定義一條LSP，直接貼配置解釋。兩個註意點，LSP是單向的，基於源於目的同時進行流量工程的隧道。
R1#sh run int tu 0
Building configuration...
Current configuration : 230 bytes
!
interface Tunnel0
ip unnumbered Loopback0 //由於是點到點隧道，ip地址沒有意義.
tunnel mode mpls traffic-eng // 在隧道下面使用這條命令，畢竟tunnel可以 有GRE， mGRE， ipv4各種奇奇怪怪的tunnel
tunnel destination 6.6.6.6 //指定目的地
tunnel mpls traffic-eng autoroute announce // 將流量引入隧道的其中一種方式，autoroute annouce 也是最常用的一種方式。
tunnel mpls traffic-eng path-option 1 explicit name CCIE //這個配置我指定 了所有explicit path的節點
no routing dynamic
end
顯示路徑
R1#sh run | s ip explicit
ip explicit-path name CCIE enable
next-address 12.1.1.2
next-address 25.1.1.5
next-address 45.1.1.4
next-address 34.1.1.3
next-address 36.1.1.6
有點亂，截圖把tunnel0和顯示路徑的配置貼下來
一些show 命令和排錯思路，IGP鄰居肯定得起來，由於RSVP-TE是軟狀態協議，RSVP的鄰居也得查看。
show isis neighbor
show ip rsvp neighbor
R2#show ip rsvp neighbor
Neighbor Encapsulation Time since msg rcvd/sent
12.1.1.1 Raw IP 00:00:07 00:00:04
25.1.1.5 Raw IP 00:00:20 00:00:37
- Neighbors inactive for more than one hour are not shown.
Use the "inactive" keyword to display them.
show mpls traffic-eng tunnels
show mpls traffic-eng tunnels tunnel 0
我截取了R2 show mpls traffic-eng tunnels的結果，可以看到進出的標簽，由於我在每個路由器上開啟了mpls label range，可以清晰明白這個標簽是哪臺路由器發放的。
R2#show mpls traffic-eng tunnels
LSP Tunnel R1_t0 is signalled, connection is up
InLabel : FastEthernet1/0, 207
OutLabel : FastEthernet2/0, 511
RSVP Signalling Info:
Src 1.1.1.1, Dst 6.6.6.6, Tun_Id 0, Tun_Instance 15
RSVP Path Info:
My Address: 25.1.1.2
Explicit Route: 25.1.1.5 45.1.1.5 45.1.1.4 34.1.1.4
34.1.1.3 36.1.1.3 36.1.1.6 6.6.6.6
Record Route: NONE
Tspec: ave rate=0 kbits, burst=1000 bytes, peak rate=0 kbits
RSVP Resv Info:
Record Route: NONE
Fspec: ave rate=0 kbits, burst=1000 bytes, peak rate=0 kbits
簡單的一個抓包，可以看到tunnel是單向的，回來的icmp reply並沒有標簽。
分析下數據層面，
R1#show ip cef 6.6.6.6
6.6.6.6/32
nexthop 6.6.6.6 Tunnel0
R1#show mpls traffic-eng tunnel tun 0
Name: R1_t0 (Tunnel0) Destination: 6.6.6.6
Status:
Admin: up Oper: up Path: valid Signalling: connected
path option 1, type explicit CCIE (Basis for Setup, path weight 50)
Config Parameters:
Bandwidth: 0 kbps (Global) Priority: 7 7 Affinity: 0x0/0xFFFF
Metric Type: TE (default)
AutoRoute: enabled LockDown: disabled Loadshare: 0 bw-based
auto-bw: disabled
Active Path Option Parameters:
State: explicit path option 1 is active
BandwidthOverride: disabled LockDown: disabled Verbatim: disabled
InLabel : -
OutLabel : FastEthernet1/0, 207 //註意標簽
RSVP Signalling Info:
Src 1.1.1.1, Dst 6.6.6.6, Tun_Id 0, Tun_Instance 15
RSVP Path Info:
My Address: 12.1.1.1
Explicit Route: 12.1.1.2 25.1.1.2 25.1.1.5 45.1.1.5
45.1.1.4 34.1.1.4 34.1.1.3 36.1.1.3
36.1.1.6 6.6.6.6
Record Route: NONE
Tspec: ave rate=0 kbits, burst=1000 bytes, peak rate=0 kbits
RSVP Resv Info:
Record Route: NONE
Fspec: ave rate=0 kbits, burst=1000 bytes, peak rate=0 kbits
Shortest Unconstrained Path Info:
Path Weight: 30 (TE)
Explicit Route: 12.1.1.1 12.1.1.2 23.1.1.2 23.1.1.3
36.1.1.3 36.1.1.6 6.6.6.6
History:
Tunnel:
Time since created: 1 hours, 33 minutes
Time since path change: 1 hours, 32 minutes
Number of LSP IDs (Tun_Instances) used: 15
Current LSP:
Uptime: 1 hours, 32 minutes
R1#
接下來就是一層層swap label的動作了。不再演示了。
MPLS TE基礎配置