Ios-Xe - Tag - Fryguy's Bloghttps://hugo.fryguy.net/tags/ios-xe/Ios-Xe - Tag - Fryguy's BlogHugo -- gohugo.ioenWed, 28 Aug 2013 12:15:34 +0000VASI – VRF Aware Service Infrastructure Interfaces and Global Route Leakinghttps://hugo.fryguy.net/2013/08/28/vasi-vrf-aware-service-infrastructure-interfaces-and-global-route-leaking/Wed, 28 Aug 2013 12:15:34 +0000Fryguyhttps://hugo.fryguy.net/2013/08/28/vasi-vrf-aware-service-infrastructure-interfaces-and-global-route-leaking/Cisco has defined a VASI interface as: VASI is implemented using virtual interfaces that provide the framework necessary to configure a firewall and NAT between VRF instances. Each interface pair is associated with two different VRF instances. The two virtual interfaces, called vasileft and vasiright, in a pair are logically wired back-to-back and are completely symmetrical. Each interface has an index. The association of the pairing is done automatically based on the two interface indexes such that vasileft automatically gets paired to vasiright. So you could look at a VASI interface as like a back-to-back connection between VRFs –  call it a virtual cable of sort.  You can also see that the traditional use of a VASI interface is to connect two VRFs, on the same router, together so they can route and NAT between each other.  But what I am saying about Global Route Leaking? Well, recently I had a problem where a client wanted to leak routes, dynamically, from a VRF to the Global table on an ASR1000 with an RP1 installed.  We could easily have done it via a physical cable, but I knew their had to be a better way.  I did some digging on the VASI interface and possible configurations and came across this –  added in IOS XE 3.10S code is the ability to actually BGP peer over the VASI interfaces to exchange routes.
You may click on the image below to view the PDF on this.]]>Cisco ASR and LACPhttps://hugo.fryguy.net/2010/12/02/cisco-asr-and-lacp/Thu, 02 Dec 2010 16:50:03 +0000Fryguyhttps://hugo.fryguy.net/2010/12/02/cisco-asr-and-lacp/I am currently working on a new site deployment utilizing some Cisco ASR1002 routers.  When we typically design a location we cross-connect the two WAN routers via a cross-over cable; this allows us to have the capability to continue to transit traffic over the connected WAN routers and WAN links if need to take down the Core at the site for maintenance.
If you look at the image below you will see three Sites – A – B – C.  Traffic that is destined to Site B from Site A will transit the connected WAN link.  So what happens if that WAN link goes down, it will transit through Site C instead.  By having the WAN routers connected via a cross-over cable, the traffic will stay at the end and not transverse the internal LAN of the site.

Ok, the background information is now out of the way. Lets continue.
Typically we use a single gigabit ethernet cross-over cable between the routers, due to hardware limitations. Well, with the ASR series we now have more interfaces that we can use for this connectivity.  What I have also found is that the ASR and IOS-XE support LACP and etherchannels.  This is a wonderful thing as it actually solves some of the problems of a single cross-over cable between routers.
So, how does one configure LACP on the ASR 1002?  It is done the same way as you would on the Nexus for L3 etherchannel. Below are the configuration commands as well as the ways to check.
For this example, we are going to create Port-Channel 12 on the router and assign interfaces G0/0/2 and G0/0/3 to the channel-group
Router#conf t
Router(config)#interface GigabitEthernet0/0/2
Router(config-if)# channel-group 12 mode active
Router(config-if)# no shut
Router(config-if)# exit
Router(config)#interface GigabitEthernet0/0/3
Router(config-if)# channel-group 12 mode active
Router(config-if)# no shut
Router(config-if)# exit
Now we can configure an IP address on the port-channel interface:
Router(config)#interface Port-channel12
Router(config-if)# ip address 10.1.1.1 255.255.255.252
T0 check the port-channel:
Router#sh int port-channel 12
Port-channel12 is up, line protocol is up
Hardware is GEChannel, address is c471.fe0c.55cb (bia c471.fe0c.55cb)
Internet address is 10.98.255.9/30
MTU 1500 bytes, BW 2000000 Kbit/sec, DLY 10 usec,
You can also look at the LACP information:
Router#sh lacp 12 neighbor
Flags:  S – Device is requesting Slow LACPDUs
F – Device is requesting Fast LACPDUs
A – Device is in Active mode       P – Device is in Passive mode
Channel group 12 neighbors
Partner’s information:
Partner Partner   LACP Partner  Partner   Partner  Partner     Partner
Port      Flags   State     Port Priority Admin Key Oper Key Port Number Port State
Gi0/0/2   SA      bndl      32768         0x0       0xC      0x3         0x3D
Gi0/0/3   SA      bndl      32768         0x0       0xC      0x4         0x3D
Router#
Now lets ping to test:
Router#p 10.1.1.2 t 1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 1 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
Router#
If you noticed I typed t 1 – that means use a 1 second timeout.  I did that in case, for some reason, it does not PING successfully I only have to wait half the normal time of 2 seconds per ping.  This might not seem like a big deal, but if you use this on some LAB test – you can save some time and frustration. 🙂

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