在Nexus上配置LISP多跳移動性

簡介

本文描述在啟用定位器身份分離協定(LISP)的網路中跨資料中心(DC)移動的IP裝置的配置和驗證，無需更改其IP地址。

必要條件

需求

思科建議您瞭解LISP的基本知識。

採用元件

本文件所述內容不限於特定軟體和硬體版本。

本文中的資訊是根據特定實驗室環境內的裝置所建立。文中使用到的所有裝置皆從已清除（預設）的組態來啟動。如果您的網路正在作用，請確保您已瞭解任何指令可能造成的影響。

背景資訊

在LISP環境中，此裝置稱為動態端點識別符號(EID)。LISP多跳移動支援子網擴展模式，該模式允許不同的DC具有相同的子網，從而允許虛擬機(VM)在遷移到其他DC時保留其分配的IP地址。

第一跳路由器(FHR)檢測動態EID的存在，並通過EID通知消息將其通知給xTR側網關。xTR註冊動態EID以對映伺服器，並對通過LISP域的流量執行LISP封裝和解除封裝功能。

部署在不同資料中心的xTR必須通過資料中心互聯(DCI)技術(如重疊傳輸虛擬化(OTV))進行連線。 在Nexus中，支援OTV組播模式。

設定

網路圖表

此影象用作文檔其餘部分的示例拓撲。

• xTR:LISP路由器可以是ITR或ETR，具體取決於流量流方向。如果流量從LISP路由器發出，則它成為該流量的ITR，接收端LISP路由器成為該路由器的ETR。

• ITR:輸入通道路由器

• ETR:輸出通道路由器

• 對映解析器(MR)：對映解析器是LISP基礎結構裝置，當您解析EID到RLOC的對映時，LISP站點ITR會將LISP對映請求查詢傳送到該裝置。

• 對映伺服器(MS):對映伺服器是LISP站點ETR向其註冊其EID字首的LISP基礎結構裝置。對映伺服器向LISP對映系統通告已註冊EID字首的聚合。所有LISP站點都使用LISP對映系統來解析EID到RLOC的對映。

• EID地址：EID地址由標識終端的IP地址和字首組成。通過解析EID到RLOC的對映，可以跨LISP站點實現EID可達性。

• 路由定位器(RLOC)地址：RLOC地址由標識IP網路中不同路由器的IP地址和字首組成。RLOC空間內的可達性是通過傳統的路由方法實現的。

• SMR:Solicit-map-request;控制平面消息，用於通知遠端xTR更新其快取的對映。

• ASM:跨子網模式；允許在不部署第2層擴展的情況下在LISP站點之間進行EID移動。

• Map-Notify:LISP消息，由檢測到EID的xTR使用，用於更新同一LISP站點中關於該發現的其他xTR。對映伺服器還使用該對映來確認已接收和處理對映暫存器。

• Map-Register:xTR使用LISP消息在對映伺服器中註冊EID。

在本文討論的示例中，流量從VM(172.16.54.200)持續流向站點3(172.16.20.1)。

West-DC

第一躍點路由器(FHR-1):

!
feature lisp
!
ip lisp etr
!
lisp dynamic-eid VM
  database-mapping 172.16.54.0/24 10.1.1.1 priority 10 weight 50
  database-mapping 172.16.54.0/24 10.2.2.2 priority 10 weight 50
  eid-notify 10.10.10.10 key 3 9125d59c18a9b015
  map-notify-group 225.1.1.1
!
interface loopback0
  ip address 10.1.1.1/32
  ip router ospf 1 area 0.0.0.0
!
interface Vlan2
  no shutdown
  lisp mobility VM
  lisp extended-subnet-mode
  ip address 172.16.54.3/24
  ip ospf passive-interface
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode
  no ip arp gratuitous request
  hsrp 1
    preempt
    priority 120
    ip 172.16.54.1
!

FHR-2:

!
feature lisp
!
ip lisp etr
!
lisp dynamic-eid VM
  database-mapping 172.16.54.0/24 10.1.1.1 priority 10 weight 50
  database-mapping 172.16.54.0/24 10.2.2.2 priority 10 weight 50
  eid-notify 10.10.10.10 key 3 9125d59c18a9b015
  map-notify-group 225.1.1.1
!
interface Vlan2
  no shutdown
 lisp mobility VM
  lisp extended-subnet-mode
  ip address 172.16.54.2/24
  ip ospf passive-interface
  ip pim sparse-mode 
  no ip arp gratuitous request
  hsrp 1
    preempt
    priority 90
    ip 172.16.54.1
!
interface loopback0
  ip address 10.2.2.2/32
  ip router ospf 1 area 0.0.0.0

xTR:

!
feature lisp
!
ip lisp itr-etr
ip lisp database-mapping 172.16.54.0/24 10.10.10.10 priority 10 weight 50
ip lisp itr map-resolver 192.168.1.1
ip lisp etr map-server 192.168.1.1 key 3 9125d59c18a9b015
!
lisp dynamic-eid VM
  database-mapping 172.16.54.0/24 10.10.10.10 priority 10 weight 50
  eid-notify authentication-key 3 9125d59c18a9b015
!
interface loopback0
  ip address 10.10.10.10/32
  ip router ospf 1 area 0.0.0.0
!

East-DC

FHR-3:

  

!
feature lisp
!
ip lisp etr
!
lisp dynamic-eid VM
  database-mapping 172.16.54.0/24 10.3.3.3 priority 10 weight 50
  database-mapping 172.16.54.0/24 10.4.4.4 priority 10 weight 50
  eid-notify 10.11.11.11 key 3 9125d59c18a9b015
  map-notify-group 225.1.1.1
!
interface Vlan2
  no shutdown
 lisp mobility VM
  lisp extended-subnet-mode
  ip address 172.16.54.4/24
  ip ospf passive-interface
  ip router ospf 1 area 0.0.0.0
  ip pim sparse-mode
  no ip arp gratuitous request
  hsrp 1
    preempt
    priority 110
    ip 172.16.54.1
!
interface loopback0
  ip address 10.3.3.3/32
  ip router ospf 1 area 0.0.0.0

FHR-4:

!
feature lisp
!
ip lisp etr
!
lisp dynamic-eid VM
  database-mapping 172.16.54.0/24 10.3.3.3 priority 10 weight 50
  database-mapping 172.16.54.0/24 10.4.4.4 priority 10 weight 50
  eid-notify 10.11.11.11 key 3 9125d59c18a9b015
 map-notify-group 225.1.1.1
!
interface Vlan2
  no shutdown
  lisp mobility VM
  lisp extended-subnet-mode
  ip pim sparse-mode 
  ip ospf passive-interface
  ip address 172.16.54.5/24
  hsrp 1
    preempt
    priority 90
    ip 172.16.54.1
!
interface loopback0
  ip address 10.4.4.4/32
  ip router ospf 1 area 0.0.0.0

xTR:

!
interface loopback0
  ip address 10.11.11.11/32
  ip router ospf 1 area 0.0.0.0
!
feature lisp
!
ip lisp itr-etr
ip lisp database-mapping 172.16.54.0/24 10.11.11.11 priority 10 weight 50
ip lisp itr map-resolver 192.168.1.1
ip lisp etr map-server 192.168.1.1 key 3 9125d59c18a9b015
!
lisp dynamic-eid VM
  database-mapping 172.16.54.0/24 10.11.11.11 priority 9 weight 50
  eid-notify authentication-key 3 9125d59c18a9b015
!

MS/MR

!
router lisp
 locator-table default
 site 1
  authentication-key cisco
  eid-prefix 172.16.54.0/24 accept-more-specifics
  exit
 !
 site 2
  authentication-key cisco
  eid-prefix 172.16.20.0/24 accept-more-specifics
  exit
 !
 ipv4 map-server
 ipv4 map-resolver

站點3

!
router lisp
 database-mapping 172.16.20.0/24 10.20.20.20 priority 10 weight 50
 ipv4 itr map-resolver 192.168.1.1
 ipv4 itr
 ipv4 etr map-server 192.168.1.1 key cisco
 ipv4 etr
 exit
!
interface Loopback1
 ip address 10.20.20.20 255.255.255.255
!
interface Loopback2
 ip address 172.16.20.1 255.255.255.0
!

操作順序

步驟1.啟動VM。

VM已通電並開始向遠端站點（即Site-3）傳送流量。 FHR-1收到此流並建立動態EID:

N7K-358-West-FHR1# show lisp dynamic-eid summary
LISP Dynamic EID Summary for VRF "default"
* = Dyn-EID learned by site-based Map-Notify
! = Dyn-EID learned by routing protocol
^ = Dyn-EID learned by EID-Notify
Dyn-EID Name   Dynamic-EID      Interface     Uptime    Last      Pending
                                                        Packet    Ping Count
VM             172.16.54.200    Vlan2         06:50:21  00:12:12  0

N7K-358-West-FHR1# show lisp dynamic-eid detail
LISP Dynamic EID Information for VRF "default"
Dynamic-EID name: VM
  Database-mapping [0] EID-prefix: 172.16.54.0/24, LSBs: 0x00000003
    Locator: 10.1.1.1, priority: 10, weight: 50
             Uptime: 06:51:34, state: up, local
    Locator: 10.2.2.2, priority: 10, weight: 50
             Uptime: 06:50:10, state: up
  Registering more-specific dynamic-EIDs
  Registering routes: disabled
  Map-Server(s): none configured, use global Map-Server
  Site-based multicast Map-Notify group: 225.1.1.1
  Extended Subnet Mode configured on 1 interfaces
  Number of roaming dynamic-EIDs discovered: 3
  Last dynamic-EID discovered: 172.16.54.1, 00:00:04 ago
  Roaming dynamic-EIDs:
    172.16.54.200, Vlan2, uptime: 06:50:31, last activity: 00:12:22
      Discovered by: packet reception

步驟2. FHR安裝LISP路由。

如步驟1所示，FHR在收到來自VM的資料包時會建立一個動態EID條目。然後在路由資訊庫(RIB)中安裝a/32路由：

N7K-358-FHR1-West-DC# show ip route 172.16.54.200
IP Route Table for VRF "default"
'*' denotes best ucast next-hop
'**' denotes best mcast next-hop
'[x/y]' denotes [preference/metric]
'%<string>' in via output denotes VRF <string>

172.16.54.200/32, ubest/mbest: 1/0, attached
    *via 172.16.54.200, Vlan2, [240/0], 06:58:08, lisp, dyn-eid
     via 172.16.54.200, Vlan2, [250/0], 06:58:45, am

步驟3. FHR通知所有其他FHR有關此動態EID。

此FHR向所有其他FHR（包括本地站點以及所有遠端站點中的FHR）傳送對映通知消息。在我們的示例中，FHR-1將有關172.16.54.200的Map-Notify傳送到本地DC上的FHR-2以及東DC上的FHR-3和FHR-4。

但只有本地站點FHR可以在其RIB中安裝該EID的路由，如下所示：

N7K-358-FHR2-West-DC# show lisp dynamic-eid detail
LISP Dynamic EID Information for VRF "default"
Dynamic-EID name: VM
 Database-mapping [0] EID-prefix: 172.16.54.0/24, LSBs: 0x00000003
 Locator: 10.1.1.1, priority: 10, weight: 50
 Uptime: 00:01:04, state: up
 Locator: 10.2.2.2, priority: 10, weight: 50
 Uptime: 00:01:53, state: up, local
 Registering more-specific dynamic-EIDs
 Registering routes: disabled
 Map-Server(s): none configured, use global Map-Server
 Site-based multicast Map-Notify group: 225.1.1.1
 Extended Subnet Mode configured on 1 interfaces
 Number of roaming dynamic-EIDs discovered: 1
 Last dynamic-EID discovered: 172.16.54.200, 00:01:04 ago
 Roaming dynamic-EIDs:
172.16.54.200, Vlan2, uptime: 00:01:04, last activity: 00:00:42
 Discovered by: site-based Map-Notify
Secure-handoff pending for sources: none

N7K-358-FHR2-West-DC#sh ip route 172.16.54.200
IP Route Table for VRF "default"
'*' denotes best ucast next-hop
'**' denotes best mcast next-hop
'[x/y]' denotes [preference/metric]
'%<string>' in via output denotes VRF <string>
172.16.54.200/32, ubest/mbest: 1/0, attached
 *via 172.16.54.200, Vlan2, [240/0], 00:00:08, lisp, dyn-eid
 via 172.16.54.200, Vlan2, [250/0], 00:01:53, am

  

步驟4. FHR將此EID更新為本地xTR。

當FHR上的兩個站點都知道EID時，它會通知其本地站點的xTR有關此EID（使用EID-Notify消息）。

East DC xTR路由器也為此字首安裝空的0路由，而West DC xTR在RIB中新增此字首。

N7K-FA8-East_xTR#show ip route 172.16.54.200
IP Route Table for VRF "default"
'*' denotes best ucast next-hop
'**' denotes best mcast next-hop
'[x/y]' denotes [preference/metric]
'%<string>' in via output denotes VRF <string>

172.16.54.200/32, ubest/mbest: 1/0, attached
    *via 172.16.54.200, Null0, [241/0], 00:00:32, lisp, dyn-eid

N7K-358-West_xTR#show lisp dynamic-eid detail
LISP Dynamic EID Information for VRF "default"
Dynamic-EID name: VM
 Database-mapping [0] EID-prefix: 172.16.54.0/24, LSBs: 0x00000001
 Locator: 10.10.10.10, priority: 10, weight: 50
 Uptime: 00:02:37, state: up, local
 Registering more-specific dynamic-EIDs
 Registering routes: disabled
 Map-Server(s): none configured, use global Map-Server
 Site-based multicast Map-Notify group: none configured
 Number of roaming dynamic-EIDs discovered: 1
 Last dynamic-EID discovered: 172.16.54.1, 00:00:06 ago
 Roaming dynamic-EIDs:
 172.16.54.200, (null), uptime: 00:00:28, last activity: 00:00:06
 Discovered by: EID-Notify
 EID-Notify Locators:
 10.1.1.1
 10.2.2.2

N7K-358-West_xTR#sh ip route 172.16.54.200
IP Route Table for VRF "default"
'*' denotes best ucast next-hop
'**' denotes best mcast next-hop
'[x/y]' denotes [preference/metric]
'%<string>' in via output denotes VRF <string>
172.16.54.0/24, ubest/mbest: 1/0
 via 10.10.13.3, Eth3/2, [110/44], 00:01:00, ospf-1, intra

本地xTR向MR/MS註冊EID:

East DC xTR還向MR/MS傳送對映註冊消息，並向它們註冊這個新發現的EID。Site-3路由器也是如此。

MS_MR#show lisp site 172.16.54.200/32
LISP Site Registration Information

Site name: 1
Allowed configured locators: any
Requested EID-prefix:
  EID-prefix: 172.16.54.200/32
    First registered:     07:11:28
    Routing table tag:    0
    Origin:               Dynamic, more specific of 172.16.54.0/24
    Merge active:         No
    Proxy reply:          No
    TTL:                  00:03:00
    State:                complete
    Registration errors:
      Authentication failures:   0
      Allowed locators mismatch: 0
    ETR 10.10.90.1, last registered 00:00:07, no proxy-reply, map-notify
                    TTL 00:03:00, no merge, hash-function sha1, nonce 0x00000000-0x00000000
                    state complete, no security-capability
                    xTR-ID N/A
                    site-ID N/A
      Locator      Local  State      Pri/Wgt  Scope
      10.10.10.10  yes    up          10/50   IPv4 none

MS_MR#sh lisp site 172.16.20.0/24
LISP Site Registration Information
Site name: 2
Allowed configured locators: any
Requested EID-prefix:
 EID-prefix: 172.16.20.0/24
 First registered: 06:30:48
 Routing table tag: 0
 Origin: Configuration, accepting more specifics
 Merge active: No
 Proxy reply: No
 TTL: 1d00h
 State: complete
 Registration errors:
 Authentication failures: 0
 Allowed locators mismatch: 0
 ETR 10.10.67.7, last registered 00:00:23, no proxy-reply, map-notify
 TTL 1d00h, no merge, hash-function sha1, nonce 0xEE339164-0xC3199AF1
 state complete, no security-capability
 xTR-ID 0x7C6C7CF6-0x2AE64A0C-0xDCBC62DA-0x79762795
 site-ID unspecified
 Locator Local State Pri/Wgt Scope
 10.20.20.20 yes up 10/50 IPv4 none

步驟5.檢驗站點1和站點3 xTR上的流量：

N7K-358-West_xTR# show ip lisp map-cache
LISP IP Mapping Cache for VRF "default" (iid 0), 3 entries
* = Locator data counters are cumulative across all EID-prefixes

0.0.0.0/1, uptime: 00:13:28, expires: 00:01:31, via map-reply
  Negative cache entry, action: forward-native

128.0.0.0/3, uptime: 00:13:28, expires: 00:01:31, via map-reply
  Negative cache entry, action: forward-native

172.16.20.0/24, uptime: 00:00:26, expires: 23:59:33, via map-reply, auth
  Locator      Uptime    State       Priority/  Data      Control       MTU
                                     Weight     in/out    in/out
  10.20.20.20  00:00:26  up          10/50      0/0*      0/0          1500

站點3 LISP對映快取條目：

Site-3#show ip lisp map-cache
LISP IPv4 Mapping Cache for EID-table default (IID 0), 2 entries

0.0.0.0/0, uptime: 01:53:04, expires: never, via static send map-request
  Negative cache entry, action: send-map-request
172.16.54.200/32, uptime: 01:50:02, expires: 22:09:57, via map-reply, complete
  Locator      Uptime    State      Pri/Wgt
 10.10.10.10  01:50:02  up          10/50

步驟6. VM從West DC移至East DC。

這些步驟是在DC之間進行VM遷移之前執行的。現在，VM從West DC移動到East DC，無需更改IP地址。當VM從West DC移動到East DC時，East DC的FHR-3收到來自VM的資料包，並將其IP地址新增到動態EID表中。然後，它將對映通知請求傳送到包括West DC的所有FHR，並且West DC收到對映通知請求後，會從West DC中存在虛擬機器時建立的動態EID表中刪除VM條目。West DC的xTR現在將空0路由安裝到VM的IP。

以下是東部DC的FHR-3上的動態EID狀態：

N7K-FA8-East_FHR3# sh lisp dynamic-eid detail
LISP Dynamic EID Information for VRF "default"
Dynamic-EID name: VM
  Database-mapping [0] EID-prefix: 172.16.54.0/24, LSBs: 0x00000003
    Locator: 10.3.3.3, priority: 10, weight: 50
             Uptime: 02:04:48, state: up, local
    Locator: 10.4.4.4, priority: 10, weight: 50
             Uptime: 02:03:27, state: up
  Registering more-specific dynamic-EIDs
  Registering routes: disabled
  Map-Server(s): none configured, use global Map-Server
  Site-based multicast Map-Notify group: 225.1.1.1
  Extended Subnet Mode configured on 1 interfaces
  Number of roaming dynamic-EIDs discovered: 1
  Last dynamic-EID discovered: 172.16.54.1, 00:00:14 ago
  Roaming dynamic-EIDs:
    172.16.54.200, Vlan2, uptime: 00:04:28, last activity: 00:03:11
      Discovered by: packet reception

N7K-FA8-East_FHR3# sh ip route 172.16.54.200
IP Route Table for VRF "default"
'*' denotes best ucast next-hop
'**' denotes best mcast next-hop
'[x/y]' denotes [preference/metric]
'%<string>' in via output denotes VRF <string>

172.16.54.200/32, ubest/mbest: 1/0, attached
    *via 172.16.54.200, Vlan2, [240/0], 00:05:00, lisp, dyn-eid
     via 172.16.54.200, Vlan2, [250/0], 00:05:10, am

因此，West FHR沒有適用於VM的動態EID，即172.16.54.200:

N7K-358-West-FHR1(config)# sh lisp dynamic-eid summary
LISP Dynamic EID Summary for VRF "default"
* = Dyn-EID learned by site-based Map-Notify
! = Dyn-EID learned by routing protocol
^ = Dyn-EID learned by EID-Notify
Dyn-EID Name   Dynamic-EID      Interface     Uptime    Last      Pending
                                                        Packet    Ping Count
VM             172.16.54.2      Vlan2         00:33:30  00:00:07  0

步驟7. West DC的xTR在路由表中新增了null 0條目：

N7K-358-West_xTR# sh ip route 172.16.54.200
IP Route Table for VRF "default"
'*' denotes best ucast next-hop
'**' denotes best mcast next-hop
'[x/y]' denotes [preference/metric]
'%<string>' in via output denotes VRF <string>

172.16.54.200/32, ubest/mbest: 1/0, attached
    *via 172.16.54.200, Null0, [241/0], 00:00:05, lisp, dyn-eid

步驟8.East xTR由FHR-3通過EID通知更新，然後East xTR向MS傳送帶有遷移的VM字首的對映暫存器：

N7K-FA8-East_xTR(config)# show lisp dynamic-eid Detail
LISP Dynamic EID Information for VRF "default"
Dynamic-EID name: VM
  Database-mapping [0] EID-prefix: 172.16.54.0/24, LSBs: 0x00000001
    Locator: 10.11.11.11, priority: 9, weight: 50
             Uptime: 02:19:51, state: up, local
  Registering more-specific dynamic-EIDs
  Registering routes: disabled
  Map-Server(s): none configured, use global Map-Server
  Site-based multicast Map-Notify group: none configured
  Number of roaming dynamic-EIDs discovered: 1
  Last dynamic-EID discovered: 172.16.54.1, 00:00:58 ago
  Roaming dynamic-EIDs:
    172.16.54.200, (null), uptime: 00:17:50, last activity: 00:00:25
      Discovered by: EID-Notify
      EID-Notify Locators:
        10.3.3.3
        10.4.4.4


MS_MR#sh lisp site 172.16.54.200
LISP Site Registration Information
Site name: 1
Allowed configured locators: any
Requested EID-prefix:
  EID-prefix: 172.16.54.200/32
    First registered:     02:02:24
    Routing table tag:    0
    Origin:               Dynamic, more specific of 172.16.54.0/24
    Merge active:         No
    Proxy reply:          No
    TTL:                  00:03:00
    State:                complete
    Registration errors:
      Authentication failures:   0
      Allowed locators mismatch: 0
    ETR 10.11.17.1, last registered 00:00:32, no proxy-reply, map-notify
                    TTL 00:03:00, no merge, hash-function sha1, nonce 0x00000000-0x00000000
                    state complete, no security-capability
                    xTR-ID N/A
                    site-ID N/A
      Locator      Local  State      Pri/Wgt  Scope
      10.11.11.11  yes    up           9/50   IPv4 none

步驟9.兩個xTR都可以更新對映快取條目。

在VM遷移之前，對於Site-3,VM的IP的RLOC為West xTR(10.10.10.10)。 將VM遷移到East DC後，一旦West xTR收到來自Site-3的流量，它就會將SMR消息傳送到Site-3路由器，以便更新East xTR(10.11.11.11)的新RLOC地址，如下所示：

Site-3#sh ip lisp map-cache
LISP IPv4 Mapping Cache for EID-table default (IID 0), 2 entries

0.0.0.0/0, uptime: 02:03:23, expires: never, via static send map-request
  Negative cache entry, action: send-map-request
172.16.54.200/32, uptime: 02:00:22, expires: 23:57:56, via map-reply, complete
  Locator      Uptime    State      Pri/Wgt
  10.11.11.11  00:02:03  up           9/50


N7K-FA8-East_xTR(config)# show ip lisp map-cache
LISP IP Mapping Cache for VRF "default" (iid 0), 1 entries
* = Locator data counters are cumulative across all EID-prefixes

172.16.20.0/24, uptime: 00:25:24, expires: 23:34:35, via map-reply, auth
  Locator      Uptime    State       Priority/  Data      Control       MTU
                                     Weight     in/out    in/out
  10.20.20.20  00:25:24  up          10/50      0/0*      0/0          1500

驗證

使用本節內容，確認您的組態是否正常運作。

驗證工作將在操作順序一節的步驟5中介紹。

疑難排解

本節提供的資訊可用於對組態進行疑難排解。

可以使用這些調試來排除受控環境中的LISP故障。

debug ip lisp mapping control

debug lisp mapping register

debug lisp smr

debug lisp ha

debug lisp loc-reach-algorithm receive-probe

debug lisp loc-reach-algorithm send-probe

debug ip mroute map_notify_addr 32 detail

debug ip lisp mapping data