Tag: vpn

IOS XR L2MPLS P2P VPN

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IOS XR L2VPN Services and Features

Troubleshooting L2VPN and Ethernet Services

EoMPLS VLAN Tag Manipulation



    

  • IOS XR is EVC based platform!
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  • AC (xconnect interface) must be configured with l2transport command
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  • IOS XR default VC type is 5/Etrhernet no matter its configured with subinterface or not. In order to change the vc type, pw-class must be configured and applied.
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  • Beware of interface MTU calculations of IOS XR! IOS XR will automatically calculate the available interface MTU based on the encapsulation used on the interface.
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  • Using of vc-type 4 may cause problems with non-evc based platforms. Use transport vlan passthrough under pw-class. https://www.dnzydn.com/2018/07/25/l2vpn-vc-types-and-control-word/
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  • IOS XE if you use subinterface for AC, vlan headers are removed. But with using EVC, service intance configuration, unless vlan poping is configured with rewrite command, vlan information will be sent over the pw.
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IOS XR var sayılan olarak her zaman xconnect’leri type 5/ETH olarak kurar ve vlan bilgisini gönderir (tüm ethernet frame’ini, FCS hariç). Ana interface veya subinterface kullanmanız farketmez. Vlan bilgisini kaldırmak için rewrite komutu kullanılmalıdır.


IOS XR var sayılan olarak type 5/ETH pseduwire kurar iken, IOS XE ise ana interface için type 5/ETH(non-EVC), subint veya EVC için type 4/VLAN kurar. IOS XE’de EVC ve subint farkı ise, vlan bilgisini iletip iletmiyeceğidir. EVC ile vlan bilgisini iletir. Tabi eğer EVC altında rewrite pop tag 1 yapılmış ise yine iletmiyeceği için sorun olur. Dökümanlarda yazan diğer bir özellik ise dummy vlan (vlan 0) kullanılmasıdır. IOS XR veya EVC tabanlı sistemler, pseudowire type 4 olarak ayarlanması durumunda farklı bir davranış sergiler. Eğer pw type 4 olarak kurulmuş ise, vlan add/remove işleminden sonra pw tarafında gönderilecek bir vlan kalmamış olabilir buda pw tipinin vlan olması ile çelişir. Bunu gidermek için pw tarafına doğru dummy vlan ekler. Tabi karşıdaki cihaz EVC tabanlı değil ise bunu anlamaz ve AC, client, tarafına bunu gönderirken dummy vlan ile gönderir. Bunu gidermek için pw-class ile transport vlan passtrough ile bu özellik kapatılır.


IOS XR : There is no difference whether or not sub inteface or main interface is configured as AC. As long as its not changed via pw-class it will AC type of 5 (ethernet). And unless rewrite command is not used it will forward client packet with its vlan.


IOS XE : There is some differences with IOS XE. If AC is configured under main interface it will type 5. If its configured under subinterface it will still type 5 but will remove AC encapsulation towards pw, and add trough the AC. If EVC is used with service instance command it will behave like IOS XR.


If local AC site is an EVC platform like IOS XR and IOS XE (service instance is used/subint) and pw type is set to type 4,  there may problem if the remote side is not an EVC based platform. EVC based platforms add a dummy vlan, vlan 0, if there is non vlan left after the rewrite command towards the pseudowire for type 5 and suppose that remote side will understand this and will remove dummy tag towards the AC. For disabling this, pw must be configured with vlan passthrough command for IOS XR.