EOMPLS set up

Answered Question
May 23rd, 2007
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Hi all


EoMPLS is configured using mpls l2transport route command etc..

what about "xconnect x.x.x.x VlanId encapsulation mpls" ?


is thsi technically different, when do u us eone and the other.


TIA


Sam

Correct Answer by Rahul Kachalia about 10 years 2 months ago

Hi Sam,


By default in EoMPLS - VLAN Mode, imposition PE transmits VLAN header transparently over the pw. If the remote side or disposition PE uses different VLAN ID, then it will perform VLAN ID rewrite before its being sent out to CE. So you may or may not use VCID value same as VLAN ID of each side, but it is required to be identical on each side.


VCID = Remote PE IP addr + Any number between 1 to 4294967295 makes a unique VC within single router. So as long as its not being duplicated with single router you are good to use it. In example :


hostname R1

!

int vlan 100

xconnect 1.1.1.1 100 encap mpls

!

int vlan 101

xconnect 2.2.2.2 100 encap mpls


both above scenario will work, but following will be considered as duplicate VC ID:


hostname R1

!

int vlan 100

xconnect 1.1.1.1 100 encap mpls

!

int vlan 101

xconnect 1.1.1.1 100 encap mpls


thanks,

rahul.

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devang_etcom Wed, 05/23/2007 - 07:59
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rahul,


then what is the use of PVC 1/100 l2transport command....


one more thing i would like to know about the DS0... i want to carry only perticular DS0 data through my IP Network instad of carrying whole T1 (24DS0).... so what will be the good way to do that... can i do it using CSU/DSU?


regards

Devang

Rahul Kachalia Wed, 05/23/2007 - 08:39
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Hi Devang,


With l2transport keyword in PVC cmd, you will now get an option to configure xconnect. Basically you are defining configured PVC as L2 switched, however you still need to configure xconnect encap mpls cmd. Remote side may have different PVC, which will get rewrite on disposition PE.


You can have FRoMPLS on individual DS0 subintf or in Port mode for complete DS0 intf. You may want to check hw-compatibility whether its a support feature or not on the platform that you are trying to implement...


thanks,

rahul.



devang_etcom Wed, 05/23/2007 - 08:43
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"You can have FRoMPLS on individual DS0 subintf or in Port mode for complete DS0 intf. You may want to check hw-compatibility whether its a support feature or not on the platform that you are trying to implement... "


rahul will you please clear little bit more on the above explanation... how to go for DS0 subinterfaces or Port mode.... will you please send me some information or link for the same...?


regards

Devang

Rahul Kachalia Wed, 05/23/2007 - 10:20
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FRoMPLS can be deployed in 2 following modes :


DLCI-to-DLCI : Each PVC from edge is carried on different pw across SP core. Only valid FR frames are transported over pw. Following is sample cfg for Per-DLCI cfg:

!

frame-re switching

!

int serial x/y

encap frame-relay <-- expects only FR frames

frame-relay intf-type dce <-- set intf as dce

type

frame-re interface-dlci switched

!

connect l2transport

xconnect x.x.x.x encap mpls

!

However on platform like GSR, you can use subintf to assign any type of per-vc L2VPN QoS policies and have another subintf offering different services, ie L3VPN/ip2tag etc. see the sample cfg on following url:


http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_feature_guide09186a008031ad96.html#wp1091660


Port Mode : Each serial intf with any type of HDLC framed pkts are transported over pw. This includes FR, PPP & HDLC encap. Following sample cfg for Port Mode.


int serial y/x

xconnect x.x.x.x encap mpls

!

with this cmd any traffic will HDLC frame (FR/PPP/HDLC) will be transparently switched over pw. On imposition PE router HDLC flag bit and FCS will be checked & removed.


thanks,

rahul.

cisco_lad2004 Wed, 05/23/2007 - 22:02
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Thanks for all the replies so far !


maybe I shoudl hae been more specific about what I want to achieve.

it is basically transporting a vlan from one PE to another accross an MPLS cloud.

I used VLANID instead of the VCID to highlight it was a VLAN I wanted to map.

Or should I simply use any VCID, but have teh config under an SVI with the appropriate VLAN.

PE1

interface VLAN 100

no ip address

xconnect Y.Y.Y.Y 40 encapsulation mpls


PE2

interface VLAN 100

no ip address

xconnect X.X.X.X 40 encapsulation mpls


where x.x.x.x & y.y.y.y are the target PE's Loopback addresses.


TIA


Sam

Correct Answer
Rahul Kachalia Thu, 05/24/2007 - 06:47
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Hi Sam,


By default in EoMPLS - VLAN Mode, imposition PE transmits VLAN header transparently over the pw. If the remote side or disposition PE uses different VLAN ID, then it will perform VLAN ID rewrite before its being sent out to CE. So you may or may not use VCID value same as VLAN ID of each side, but it is required to be identical on each side.


VCID = Remote PE IP addr + Any number between 1 to 4294967295 makes a unique VC within single router. So as long as its not being duplicated with single router you are good to use it. In example :


hostname R1

!

int vlan 100

xconnect 1.1.1.1 100 encap mpls

!

int vlan 101

xconnect 2.2.2.2 100 encap mpls


both above scenario will work, but following will be considered as duplicate VC ID:


hostname R1

!

int vlan 100

xconnect 1.1.1.1 100 encap mpls

!

int vlan 101

xconnect 1.1.1.1 100 encap mpls


thanks,

rahul.

cisco_lad2004 Tue, 06/05/2007 - 13:56
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Hi again


I amnow configuring teh below set up:


RTR1 trunk-subif-RTR2 if -MPLS IF-if RTR3 trunk--trunk RTR4


RTR1 is the new device I need to connect VIA Vlan to RTR4 accross MPLS could. it has an SVI with /30.


RTR1- trunk terminates in RTR2 dot1Q subif which is where I configured xconnect to RTR3 Loopback.


RTR3 no config


RTR4 SVI /30 same subnet as RTR1


I understand I need to configure another subif with xconnect pinting to RTR2 Loopback.. but where should this be. normallt RTR3 on interface facing RTR4 as a subif .1q. but this is a trunk and no su-bif can be configured.


how can i get this to work ?


TIA


Sam


devang_etcom Tue, 06/05/2007 - 14:05
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SAM,


now you are going to configure the EoMPLS but in VLAN mode. it will work same way as you have EoMPLS but here now PSEUDOWIRE will carry the 802.1Q tagged data from one PE router to Other PE router. in port mode you are configuring the XCONNECT on real interface but now you will configure it on the Subinterfaces... nothing much


regards

Devang

cisco_lad2004 Tue, 06/05/2007 - 14:15
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Thanks for reply Devang


on RTR1 I have an SVI and trunk facing RTR2 or PE.


on RTR2/PE1 I configured xconnect on 802.1q subif


on RTR3 /PE2 I cannot configure xconnect on subif facing RTR4 as the link betwen them is trunk.


on RTR4 I have an SVI with same subnet as RTR1.


I think it would work fine if RTR2 and RTR4 did not have trunk both sides of link so I can have a subif on RTR3 / PE2.


did I misunderstood your reply ?


Sam

Rahul Kachalia Tue, 06/05/2007 - 15:32
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I m not following your exact comment about RTR3/PE2 configuration. Looking from your cfg requirement it seems you wanted RTR1 and RTR4 communicate each other over same or different VLAN IDs. Each of this routers are connected to PEs, now why cant you configure RTR3 a subintf with xconnect cmd?!


If for any reason that you cannot configure xconnect under subintf on RTR3, you can still make it working with Ethernet Interworking configuration on both PEs. Meaning on RTR1 you can have VLAN tagged frames sent/receive to RTR2 but RTR3 will sends/receives untagged ethernet frames to RTR4...


thanks,

rahul.

cisco_lad2004 Wed, 06/06/2007 - 00:10
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Thats right ! I need RTR1 to connect to RTR4 thru MPLS cloud.

RTR1 - PE1, I configured SVI 700 on RTR1 and


interface TenGigabitEthernet1/2.770

encapsulation dot1Q 770

xconnect 10.10.10.2 770 encapsulation mpls


RTR2-PE2, I configured SVI 700 , but PE2 has a trunk to RTR2 so I cannot configure subif. I used

interface Vlan770

no ip address

xconnect 10.110.10.1 770 encapsulation mpls


is this how it should be ?


Sam

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