Device : Quidway S7703
Version: V200R008C00SPC500
We are going to merge 2 big networks ; The first is a Huawei network (150 switchs mpls) and the second is a Cisco Network (100 routers). IGP on Huawei is OSPF and on Cisco is ISIS. We will deploy ISIS gradually on our Huawei network.
And we need to understand how the interconnection works, because there are many customers on these networks so we will use for test a MPLS between a Cisco-7606 and Huawei S7700.
When we use full Huawei network, we can view “Initialization Message’’. When we use full Cisco network, we can view “Initialization message’’. But, when we use Huawei and Cisco network, we don’t view “initialization message”.
On Full Cisco Network, Max PDU Length is 0. On Full Huawei Network, Max PDU Length is 4096. We need to know if that is a problem in the future, if we use the both on the same network.
So main questions are :
1. How is negociated MaxPDU length when the value for the first router is 0 (Cisco) and the second router is 4096 (Huawei)?
2. How can we display that MaxPDU was negociated ?
Alarm InformationNo alarm present, we noticed just the Initialization message was not present at the begining.
Handling ProcessChecking the Init message in terminal of Huawei :
Sep 29 2017 11:51:06.860.1+02:00 DST LAB-S77 LDP/7/PDU:
11:1546: Receive TCP Message from Peer: 192.168.95.25. Message content:
02 00 00 16 00 09 7d 99 05 00 00 0e 00 01 00 b4
00 00 00 00 c0 a8 5f 17 00 00
The message type: Initialization Message..
<LAB-S77>
Sep 29 2017 11:51:06.860.2+02:00 DST LAB-S77 LDP/7/PDU:
11:3812: LDP msg added to ssn's nor-msg-list. (MsgType:0x200|0x0, Ssn:192.168.95.25)
<LAB-S77>
Sep 29 2017 11:51:06.860.3+02:00 DST LAB-S77 LDP/7/PDU:
11:3894: Send TCP Message to Peer: 192.168.95.25. Message content:
02 00 00 16 00 57 b0 27 05 00 00 0e 00 01 00 2d
00 00 10 00 c0 a8 5f 19 00 00
The message type: Initialization Message..
<LAB-S77>
2. Checking the MPLS LDP peer :
<LAB-S77>dis mpls ldp peer
LDP Peer Information in Public network
A '*' before a peer means the peer is being deleted.
------------------------------------------------------------------------------
PeerID TransportAddress DiscoverySource
------------------------------------------------------------------------------
192.168.95.25:0 192.168.95.25 Vlanif4088
------------------------------------------------------------------------------
TOTAL: 1 Peer(s) Found.
Checking the MPLS LDP session :
<LAB-S77>dis mpls ldp session
LDP Session(s) in Public Network
Codes: LAM(Label Advertisement Mode), SsnAge Unit(DDDD:HH:MM)
A '*' before a session means the session is being deleted.
------------------------------------------------------------------------------
PeerID Status LAM SsnRole SsnAge KASent/Rcv
------------------------------------------------------------------------------
192.168.95.25:0 Operational DU Passive 0000:00:07 29/34
------------------------------------------------------------------------------
TOTAL: 1 session(s) Found.
Checking also MPLS LSP :
Checking also the l2vc and is up:
Root CauseFor the first issue, the root cause was that the Init message arrive during a different path and the negotiated value works like this: from the RFC we select the small value. But if the value is below 255. RFC rule use the default value 4096.
SolutionQuestion 1 answer :
It chooses the smaller one (if the peer value is zero we will use the local value).
Question 2 answer:
We can use command below :
1. For Huawei vs Huawei:
[S6720EI-20.21-diagnose]dis mpls ldp peer verbose
LDP Peer Information in Public network
------------------------------------------------------------------------------
Peer LDP ID : 1.1.1.40:0
Peer Max PDU Length : 4096 Peer Transport Address : 1.1.1.40
Peer Loop Detection : Off Peer Path Vector Limit : ----
Peer FT Flag : Off Peer Keepalive Timer : 45 Sec
Recovery Timer : ---- Reconnect Timer : ----
Peer Type : Local
Peer Label Advertisement Mode : Downstream Unsolicited
Peer Discovery Source : Vlanif2
Peer Deletion Status : No
Capability-Announcement : Off
Peer mLDP P2MP Capability : Off
Peer mLDP MP2MP Capability : Off
Peer mLDP MBB Capability : Off
------------------------------------------------------------------------------
2. For Huawei vs CISCO
[S6720EI-20.21-diagnose]
<LAB-S77>dis mpls ldp peer verbose
LDP Peer Information in Public network
------------------------------------------------------------------------------
Peer LDP ID : 192.168.95.25:0
Peer Max PDU Length : 0 Peer Transport Address : 192.168.95.25
Peer Loop Detection : Off Peer Path Vector Limit : ----
Peer FT Flag : Off Peer Keepalive Timer : 180 Sec
Recovery Timer : ---- Reconnect Timer : ----
Peer Type : Local&Remote
Peer Label Advertisement Mode : Downstream Unsolicited
Peer Discovery Source : remote peer: 192.168.95.25
Vlanif4088
Peer Deletion Status : No
Capability-Announcement : Off
Peer mLDP P2MP Capability : Off
Peer mLDP MP2MP Capability : Off
Peer mLDP MBB Capability : Off
------------------------------------------------------------------------------
