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本文說明如何配置和驗證單一以應用為中心的基礎設施(ACI)交換矩陣上同一終端組(EPG)中的第2層(L2)組播。
思科建議您瞭解以下主題:
附註:有關IGMP監聽的詳細資訊,請參閱思科APIC和IGMP監聽2層組播配置文檔。
本文中的資訊係根據以下軟體和硬體版本:
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。如果您的網路運作中,請確保您瞭解任何指令可能造成的影響。
L2組播是指在L2網段(網橋域(BD)/子網)上轉發的IP組播資料包,而不是L2非IP組播資料包,這些資料包是具有目的地組播MAC地址且沒有IP報頭的組播資料包。L2組播也不包括本地鏈路組播(224.0.0.0/24)。 本地鏈路組播始終轉發到BD中的所有埠。
ACI中的L2組播僅在BD內轉發。如果您有多個EPG使用相同的BD,則無論各EPG之間簽訂了什麼合約,組播流量都會在所有EPG中泛洪。
思科ACI在枝葉和主幹交換機之間構建的重疊組播樹上轉發組播幀。第2層流量使用轉發標籤(FTAG)樹在多條冗餘成本相同的鏈路上提供高效的負載均衡。有關FTAG樹的詳細資訊,請參閱ACI基礎文檔。
注意:建議您不要在BD上禁用IGMP監聽。如果您禁用IGMP監聽,則可能會看到組播效能降低,因為BD內發生了過多虛假泛洪。
以下是組態步驟的摘要。除了啟用IGMP查詢器外,L2組播沒有太多配置。
本節介紹詳細的配置步驟。
圖中顯示配置的高層次方法。ACI Initial Deployment文檔中提供了有關訪問策略的其他詳細資訊。
如果訪問策略已經到位,則可以跳過此步驟。
預設情況下,BD使用在「通用」租戶中預定義的預設IGMP監聽策略。
預設情況下,BD子網下未啟用IGMP查詢器,這也適用於基於傳統NXOS或Cisco IOS®的部署。
必須在各自的IGMP監聽策略和BD子網下啟用兩位IGMP查詢器。
附註:由於啟用了Enable querier的IGMP監聽策略需要源IP地址來傳送IGMP查詢,因此需要在BD子網下配置啟用IGMP Querier IP。否則,枝葉交換機不會將IGMP查詢傳送到組播接收器。
始終建議在啟用IGMP查詢器的情況下配置新的IGMP監聽策略,而不是使用預設的IGMP監聽策略。請注意,預設的IGMP監聽策略預設情況下未啟用IGMP查詢器,並且預設與每個BD關聯。更改預設IGMP監聽策略下的任何配置會影響與預設IGMP監聽策略連線的每個BD,因此建議不要更改ACI中的預設IGMP監聽策略引數。
附註:只有在BD子網配置了Querier IP時,才需要Enable querier設定。如果IGMP查詢器在ACI之外,則不需要此配置。
lf101# show ip igmp snooping querier Vlan IP Address Version Expires Port 21 10.100.0.254 v3 00:01:06 Switch querier
lf102# show ip igmp snooping querier Vlan IP Address Version Expires Port 19 10.100.0.254 v3 00:01:46 Switch querier
使用本節內容,確認您的組態是否正常運作。
此 MO query
命令顯示IGMP查詢器策略已啟用查詢器。
apic1# moquery -d uni/tn-TN_D/snPol-TN_D_IGMP_snooping_POL Total Objects shown: 1 # igmp.SnoopPol name : TN_D_IGMP_snooping_POL adminSt : enabled annotation : childAction : ctrl : querier descr : dn : uni/tn-TN_D/snPol-TN_D_IGMP_snooping_POL extMngdBy : lastMbrIntvl : 1 lcOwn : local modTs : 2022-01-26T19:32:18.660+00:00 nameAlias : ownerKey : ownerTag : queryIntvl : 125 rn : snPol-TN_D_IGMP_snooping_POL rspIntvl : 10 startQueryCnt : 2 startQueryIntvl : 31 status : uid : 15374
此 MO query
命令顯示BD子網上也啟用了IGMP查詢器。
apic1# moquery -c fvSubnet -f 'fv.Subnet.ip=="10.100.0.254/24"' Total Objects shown: 1 # fv.Subnet ip : 10.100.0.254/24 annotation : childAction : ctrl : querier <<descr : dn : uni/tn-TN_D/BD-L2_Mcast_BD/subnet-[10.100.0.254/24] extMngdBy : lcOwn : local modTs : 2021-12-28T19:28:54.860+00:00 monPolDn : uni/tn-common/monepg-default name : nameAlias : preferred : no rn : subnet-[10.100.0.254/24] scope : private status : uid : 15374 virtual : no
此 MO query
命令顯示BD配置的驗證。
apic1# moquery -c fvBD -f "fv.BD.name==\"L2_Mcast_BD\"" Total Objects shown: 1 # fv.BD name : L2_Mcast_BD OptimizeWanBandwidth : no annotation : arpFlood : yes bcastP : 225.1.156.240 childAction : configIssues : descr : dn : uni/tn-TN_D/BD-L2_Mcast_BD epClear : no epMoveDetectMode : extMngdBy : hostBasedRouting : no intersiteBumTrafficAllow : no intersiteL2Stretch : no ipLearning : yes ipv6McastAllow : no lcOwn : local limitIpLearnToSubnets : yes llAddr : :: mac : 00:22:BD:F8:19:FF mcastAllow : no modTs : 2021-12-25T23:47:57.717+00:00 monPolDn : uni/tn-common/monepg-default mtu : inherit multiDstPktAct : bd-flood nameAlias : ownerKey : ownerTag : pcTag : 49154 rn : BD-L2_Mcast_BD scope : 2490368 seg : 16351140 status : type : regular uid : 15374 unicastRoute : yes unkMacUcastAct : proxy unkMcastAct : flood v6unkMcastAct : flood vmac : not-applicable
此輸出顯示leaf-101已連線到組播源10.100.0.10的驗證。
lf101# show endpoint ip 10.100.0.10 detail Legend: s - arp H - vtep V - vpc-attached p - peer-aged R - peer-attached-rl B - bounce S - static M - span D - bounce-to-proxy O - peer-attached a - local-aged m - svc-mgr L - local E - shared-service +-----------------------------------+---------------+-----------------+--------------+-------------+------------------------------+ VLAN/ Encap MAC Address MAC Info/ Interface Endpoint Group Domain VLAN IP Address IP Info Info +-----------------------------------+---------------+-----------------+--------------+-------------+------------------------------+ 20 vlan-1900 0011.0100.0001 L eth1/47 TN_D:Multicast_Servers:L2_Mcast_EPG TN_D:VRF_A vlan-1900 10.100.0.10 L eth1/47
此輸出顯示leaf-102已連線到組播接收器10.100.0.20的驗證。
lf102# show endpoint ip 10.100.0.20 detail Legend: s - arp H - vtep V - vpc-attached p - peer-aged R - peer-attached-rl B - bounce S - static M - span D - bounce-to-proxy O - peer-attached a - local-aged m - svc-mgr L - local E - shared-service +-----------------------------------+---------------+-----------------+--------------+-------------+------------------------------+ VLAN/ Encap MAC Address MAC Info/ Interface Endpoint Group Domain VLAN IP Address IP Info Info +-----------------------------------+---------------+-----------------+--------------+-------------+------------------------------+ 17 vlan-1900 0011.0200.0001 L eth1/47 TN_D:Multicast_Servers:L2_Mcast_EPG TN_D:VRF_A vlan-1900 10.100.0.20 L eth1/47
lf101# vsh_lc module-1# debug platform internal roc elam asic 0 module-1(DBG-elam)# trigger reset module-1(DBG-elam)# trigger init in-select 6 out-select 0 module-1(DBG-elam-insel6)# set outer ipv4 src_ip 10.100.0.10 dst_ip 239.100.0.10 module-1(DBG-elam-insel6)# start module-1(DBG-elam-insel6)# status ELAM STATUS =========== Asic 0 Slice 0 Status Triggered module-1(DBG-elam-insel6)# module-1(DBG-elam-insel6)# ereport Python available. Continue ELAM decode with LC Pkg ELAM REPORT <snip..> ====================================================================================================================================================== Captured Packet ====================================================================================================================================================== ------------------------------------------------------------------------------------------------------------------------------------------------------ Outer Packet Attributes ------------------------------------------------------------------------------------------------------------------------------------------------------ Outer Packet Attributes : l2mc ipv4 ip ipmc ipv4mc udp Opcode : OPCODE_L3MC ------------------------------------------------------------------------------------------------------------------------------------------------------ Outer L2 Header ------------------------------------------------------------------------------------------------------------------------------------------------------ Destination MAC : 0100.5E64.000A <<802.1Q tag is valid : no( 0x0 ) CoS : 0( 0x0 ) Access Encap VLAN : 0( 0x0 ) ------------------------------------------------------------------------------------------------------------------------------------------------------ Outer L3 Header ------------------------------------------------------------------------------------------------------------------------------------------------------ L3 Type : IPv4 IP Version : 4 DSCP : 0 IP Packet Length : 1362 ( = IP header(28 bytes) + IP payload ) Don't Fragment Bit : not set TTL : 64 IP Protocol Number : UDP IP CheckSum : 31679( 0x7BBF ) Destination IP : 239.100.0.10 <<
<snip...> ------------------------------------------------------------------------------------------------------------------------------------------------------ Sideband SB Multicast Information ------------------------------------------------------------------------------------------------------------------------------------------------------ BD : 11266( 0x2C02 ) Source is l3 interface : no FTAG : 4( 0x4 ) <<< FTAG value 4 assigned by lf101 <snip..>
FTAG ID是基於負載雜湊演算法(0到12)分配的。 FTAG值是不可預測的,並且即使枝葉節點和目標BD GiPO相同,該值也不相同。
225.1.156.140的二進位制= 11100001.00000001.10011100.1111000
目的地GIPO最後一個八位值的最後4位為「0000」,因此最後4位元(介於0到12之間)會新增到FTAG值。
此輸出顯示GIPO路由和輸出介面(OIF)清單。
lf101# show isis internal mcast routes gipo IS-IS process: isis_infra VRF : default GIPo Routes ==================================== System GIPo - Configured: 0.0.0.0 Operational: 239.255.255.240 ==================================== GIPo: 225.0.0.0 [LOCAL] OIF List: Ethernet1/49.14 GIPo: 225.0.73.208 [TRANSIT] OIF List: GIPo: 225.1.110.160 [LOCAL] OIF List: Ethernet1/49.14 GIPo: 225.1.149.64 [LOCAL] OIF List: Ethernet1/49.14 GIPo: 225.1.156.240 [LOCAL] OIF List: Ethernet1/49.14 GIPo: 225.1.179.176 [TRANSIT] OIF List: GIPo: 225.1.192.0 [TRANSIT] OIF List: GIPo: 239.255.255.224 [LOCAL] OIF List: Ethernet1/49.14 GIPo: 239.255.255.240 [LOCAL] OIF List: Ethernet1/49.14
此輸出顯示FTAG值和OIF清單。
lf101# show isis internal mcast routes ftag IS-IS process: isis_infra VRF : default FTAG Routes ==================================== System ftag order: NEW Phantom Spine Capable: NO FTAG ID: 0 [Enabled] Cost:( 1/ 13/ 0) ---------------------------------- Root port: Ethernet1/49.14 OIF List: FTAG ID: 1 [Enabled] Cost:( 1/ 1/ 0) ---------------------------------- Root port: Ethernet1/49.14 OIF List: FTAG ID: 2 [Enabled] Cost:( 1/ 2/ 0) ---------------------------------- Root port: Ethernet1/49.14 OIF List: FTAG ID: 3 [Enabled] Cost:( 1/ 3/ 0) ---------------------------------- Root port: Ethernet1/49.14 OIF List: FTAG ID: 4 [Enabled] Cost:( 1/ 4/ 0) ---------------------------------- Root port: Ethernet1/49.14 OIF List: FTAG ID: 5 [Enabled] Cost:( 1/ 5/ 0) ---------------------------------- Root port: Ethernet1/49.14 OIF List: FTAG ID: 6 [Enabled] Cost:( 1/ 6/ 0) ---------------------------------- Root port: Ethernet1/49.14 OIF List: FTAG ID: 7 [Enabled] Cost:( 1/ 7/ 0) ---------------------------------- Root port: Ethernet1/49.14 OIF List: FTAG ID: 8 [Enabled] Cost:( 1/ 8/ 0) ---------------------------------- Root port: Ethernet1/49.14 OIF List: FTAG ID: 9 [Enabled] Cost:( 1/ 9/ 0) ---------------------------------- Root port: Ethernet1/49.14 OIF List: FTAG ID: 10 [Enabled] Cost:( 1/ 10/ 0) ---------------------------------- Root port: Ethernet1/49.14 OIF List: FTAG ID: 11 [Enabled] Cost:( 1/ 11/ 0) ---------------------------------- Root port: Ethernet1/49.14 OIF List: FTAG ID: 12 [Enabled] Cost:( 1/ 12/ 0) ---------------------------------- Root port: Ethernet1/49.14 OIF List: FTAG ID: 13 [Disabled] FTAG ID: 14 [Disabled] FTAG ID: 15 [Disabled]
Spine201# vsh_lc <<< (OR "ssh root@lcX" if spine is modular). (Please engage TAC for spine ELAM)
module-1# debug platform internal roc elam asic 0
module-1(DBG-elam)# trigger reset
module-1(DBG-elam)# trigger init in-select 14 out-select 0
module-1(DBG-elam-insel6)# set inner ipv4 src_ip 10.100.0.10 dst_ip 239.100.0.10
module-1(DBG-elam-insel6)# start
module-1(DBG-elam-insel6)# status
module-1(DBG-elam-insel6)# ereport
------------------------------------------------------------------------------------------------------------------------------------------------------ Inner L2 Header ------------------------------------------------------------------------------------------------------------------------------------------------------ Inner Destination MAC : 0100.5E64.000A Source MAC : 0011.0100.0001 802.1Q tag is valid : no CoS : 0 Access Encap VLAN : 0 ------------------------------------------------------------------------------------------------------------------------------------------------------ Outer L3 Header ------------------------------------------------------------------------------------------------------------------------------------------------------ L3 Type : IPv4 DSCP : 0 Don't Fragment Bit : 0x0 TTL : 32 IP Protocol Number : UDP Destination IP : 225.1.156.244 <<<< BD GIPO + FTAG 4 (binary 11100001.00000001.10011100.11110100) Source IP : 10.1.160.64 <<<< Leaf 101 infra TEP address ------------------------------------------------------------------------------------------------------------------------------------------------------ Inner L3 Header ------------------------------------------------------------------------------------------------------------------------------------------------------ L3 Type : IPv4 DSCP : 0 Don't Fragment Bit : 0x0 TTL : 64 IP Protocol Number : UDP Destination IP : 239.100.0.10 Source IP : 10.100.0.10 <snip...>
------------------------------------------------------------------------------------------------------------------------------------------------------ Sideband SB Multicast Information ------------------------------------------------------------------------------------------------------------------------------------------------------ BD : 3( 0x3 ) Source is l3 interface : no FTAG : 4( 0x4 ) <snip...>
sp201# show isis internal mcast routes gipo IS-IS process: isis_infra VRF : default GIPo Routes ==================================== System GIPo - Configured: 0.0.0.0 Operational: 239.255.255.240 ==================================== GIPo: 225.0.0.0 [TRANSIT] OIF List: Ethernet1/2.35 Ethernet1/1.36 GIPo: 225.0.0.16 [TRANSIT] OIF List: <snip..> GIPo: 225.1.156.240 [TRANSIT] OIF List: Ethernet1/2.35 Ethernet1/1.36 <snip...> sp201# show isis internal mcast routes ftag IS-IS process: isis_infra VRF : default FTAG Routes ==================================== System ftag order: NEW System ftag preference: 2 Max Fabric System ftag preference: 2 Phantom Spine Capable: NO FTAG ID: 0 [Root] [Enabled] Cost:( 0/ 0/ 0) ---------------------------------- Root port: - OIF List: Ethernet1/2.35 Ethernet1/1.36 FTAG ID: 1 [Root] [Enabled] Cost:( 0/ 0/ 0) ---------------------------------- Root port: - OIF List: Ethernet1/2.35 Ethernet1/1.36 FTAG ID: 2 [Root] [Enabled] Cost:( 0/ 0/ 0) ---------------------------------- Root port: - OIF List: Ethernet1/2.35 Ethernet1/1.36 FTAG ID: 3 [Root] [Enabled] Cost:( 0/ 0/ 0) ---------------------------------- Root port: - OIF List: Ethernet1/2.35 Ethernet1/1.36 FTAG ID: 4 [Root] [Enabled] Cost:( 0/ 0/ 0) ---------------------------------- Root port: - OIF List: Ethernet1/2.35 <<<snip...> sp201# show lldp neighbors Capability codes: (R) Router, (B) Bridge, (T) Telephone, (C) DOCSIS Cable Device (W) WLAN Access Point, (P) Repeater, (S) Station, (O) Other Device ID Local Intf Hold-time Capability Port ID lf101 Eth1/1 120 BR Eth1/49 <<< Spine received packet from Leaf 101 lf102 Eth1/2 120 BR Eth1/49 <<< forward packet to Leaf 102 (and not back to Leaf 101) Total entries displayed: 2
lf102# vsh_lc module-1# debug platform internal roc elam asic 0 module-1(DBG-elam)# trigger reset module-1(DBG-elam)# trigger init in-select 14 out-select 0 module-1(DBG-elam-insel14)# set inner ipv4 src_ip 10.100.0.10 dst_ip 239.100.0.10 module-1(DBG-elam-insel14)# start module-1(DBG-elam-insel14)# status ELAM STATUS =========== Asic 0 Slice 0 Status Triggered module-1(DBG-elam-insel14)# ereport ------------------------------------------------------------------------------------------------------------------------------------------------------ Outer L3 Header ------------------------------------------------------------------------------------------------------------------------------------------------------ L3 Type : IPv4 DSCP : 0 Don't Fragment Bit : 0x0 TTL : 31 IP Protocol Number : UDP Destination IP : 225.1.156.244 Source IP : 10.1.160.64 ------------------------------------------------------------------------------------------------------------------------------------------------------ Inner L3 Header ------------------------------------------------------------------------------------------------------------------------------------------------------ L3 Type : IPv4 DSCP : 0 Don't Fragment Bit : 0x0 TTL : 64 IP Protocol Number : UDP Destination IP : 239.100.0.10 Source IP : 10.100.0.10 ------------------------------------------------------------------------------------------------------------------------------------------------------
lf102# show ip igmp snooping group Type: S - Static, D - Dynamic, R - Router port, F - Fabricpath core port Vlan Group Address Ver Type Port list 16 239.100.0.10 v2 D Eth1/47
IGMP查詢器要求包括:
本節提供的資訊可用於對組態進行疑難排解。
使用以下命令排除L2 IGMP故障:
show endpoints IP
detail
show ip igmp snoop groups vlan x
show ip igmp snoop groups vlan x detail
show ip igmp snooping mrouter
moquery -c fmcast.Grp
修訂 | 發佈日期 | 意見 |
---|---|---|
1.0 |
28-Feb-2022 |
初始版本 |