Ciscoman's notes (Записки цыщика c дипломом)

I'm Cisco Champion Community member for 2017!

I'm Cisco Champion Community member for 2017!
"Cisco Champions are passionate about Cisco and happy to share our knowledge, experience, and feedback."

пятница, 22 августа 2014 г.

EIGRP named mode "passive-interface default" vs "af-interface default shutdown" and Virtual-Template

    As you probably know, EIGRP named mode is a new style standard for EIGRP configuration in current IOS versions. So I would like to note some interesting points on configuration.
May be not so interesting really, but this significant difference was noted between "af-interface default shutdown" and "af-interface default passive" (except it's primary goals ;)) so we need to be accurate with behavior related to Virtual-Template interfaces. Let's look at the firs useful application of "shutdown". It is very handy to use it in OSPF-like interface configuration style to include only required interfaces in routing protocol:

interface Virtual-Template1 type tunnel
 ip ospf 2 area 1

And if our Virtual-Access is connected, OSPF will enable process on this interface also:

R1#sh ip ospf interface b

Virtual-Access1            10.0.1.2        YES unset  up                    up
Virtual-Template1          10.0.1.2        YES unset  up                    down

R1#sh ip ospf interface b
Interface    PID   Area            IP Address/Mask    Cost  State Nbrs F/C
Vi1          2     1               Unnumbered Lo0     1     P2P   1/1

In this example we are enabling EIGRP only on Virtual-Template1 interface similarly to OSPF:

router eigrp TEST
 !
 address-family ipv4 unicast autonomous-system 1
  !
  af-interface default
   shutdown
  exit-af-interface
  !
  af-interface Virtual-Template1
   no shutdown
  exit-af-interface
  !
  topology base
  exit-af-topology
  network 0.0.0.0
 exit-address-family

But note significant difference. EIGRP will not be enabled on Virtual-Access interface although it is up and running:

R1#sh ip int b
Virtual-Access1            10.0.1.2        YES unset  up                    up
Virtual-Template1          10.0.1.2        YES unset  up                    down 
R1#sh ip eigrp neighbors
EIGRP-IPv4 VR(IPSEC) Address-Family Interfaces for AS(1)
                              Xmit Queue   PeerQ        Mean   Pacing Time   Multicast    Pending
Interface              Peers  Un/Reliable  Un/Reliable  SRTT   Un/Reliable   Flow Timer   Routes
Vt1                      0        0/0       0/0           0       6/6            0           0
 Now let's look at "passive-interface default" behaviour:

router eigrp TEST
 !
 address-family ipv4 unicast autonomous-system 1
  !
  af-interface default
   passive-interface
  exit-af-interface
  !
  af-interface Virtual-Template1
   no passive-interface
  exit-af-interface
  !
  topology base
  exit-af-topology
  network 0.0.0.0
 exit-address-family

And as you can see, It is all fine, up and running in such way, just as expected:
R1#sh ip int b
Virtual-Access1            10.0.1.2        YES unset  up                    up
Virtual-Template1          10.0.1.2        YES unset  up                    down
R1#sh ip eigrp neighbors
EIGRP-IPv4 VR(IPSEC) Address-Family Neighbors for AS(1)
H   Address                 Interface              Hold Uptime   SRTT   RTO  Q  Seq
                                                   (sec)         (ms)       Cnt Num
0   10.0.1.1                Vi1                      10 00:00:09  479  2874  0  5
All testing were made with  IOS version 15.2(4)M6. Thank you for interest to this blog post. Please say couple words in comments if it was usefull/interesting, because it seems to me nobody interested in my posts :(

Комментариев нет:

Отправить комментарий

Постоянные читатели

Поиск по этому блогу