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I am trying to configure BFD for both OSPF and BGP on the Cisco ASR1000 (non X) and Juniper QFX5110. The problem is that the QFX doesn't officially support BFD timers lower than 1000ms without potential flaps.

QFX5000 Series switches and EX4600 switches do not support minimum interval values of less than 1 second.

On the other hand, the ASR1000 doesn't seem to support a BFD rx_int of greater than 999ms.

lns-02(config-subif)#bfd interval ?
  <750-999>  Milliseconds

Would an upgrade of IOS-XE on the ASR1000 allow me to increase this value up to 1000ms and higher? Or is this a hardware limitation?

If 1000ms is not possible, has anyone used particular BFD timers that they've found reliable in this combination? Particularly QFX5110s with ASRs?

A few things to note:

  • The ASR1000 is running Cisco IOS XE Software, Version 03.16.07b.S - Extended Support Release
  • I found a document that suggests this might be hardware related, but I'm unsure.
  • I have some ASR1001-X routers running newer IOS-XE that can do BFD timers of much higher, up to 9,999ms. They are running newer IOS-XE: Cisco IOS XE Software, Version 16.09.04
bdr-01(config-subif)#bfd interval ?
  <750-9999>  Milliseconds

Here's my intended configuration on the ASR1001 and ASR1001-X devices:

 bfd interval 1000 min_rx 1100 multiplier 3

Here's my intended configuration on the QFX:

        bfd-liveness-detection {
            minimum-interval 1000;
            minimum-receive-interval 1100;
            multiplier 3;
        }
  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can post and accept your own answer. – Ron Maupin Dec 31 '20 at 19:43
3

I strongly recommend you look at upgrading your IOS to something a lot more recent as IOS XE 3.16 is no longer in support for Security Vulnerabilities as of August 2016. For your reference, I have an ASR1001 (non X) running IOS XE 16.06.08 and as seen below, this appears to support a much larger BFD interval than 3.16.

<redacted>#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
<redacted>(config)#interface TenGigabitEthernet0/0/0.2156
<redacted>(config-subif)#bfd interval ?
  <50-9999>  Milliseconds

Edit: Was actually looking at an ASR1001-X. As OP suggested, 1001s on 3.16 (latest since EOL/EOS) only support BFD intervals of up to 999ms.

  • 1
    Thanks for this! I was hoping an upgrade would do it. I would love to upgrade these units, but from what I can tell they only support 3.x? Mind linking to where you got your version? The latest version I can find on Cisco's website is asr1001-universal.03.16.10.S.155-3.S10-ext.bin. I am of course running 16.x on the ASR1001-X routers. – Geekman Dec 21 '20 at 9:44
  • @Geekman, I must apologise. I was actually logged into a 1001-X, had the wrong terminal open! I guess the first indicator should have been the TenGig Interface I looked at.. Looking at my 1001 (actually non -X) I do also see the interval at 999 MS too. I'm not too sure about interop with the QFX so I will update my response. – ditrapanij Dec 21 '20 at 13:09
  • Heh, yeah I noticed the Te interface but I was hoping maybe you had a 10g module. Hopefully there's still a solution, but I am thinking I probably need to work with the 999ms limit. – Geekman Dec 21 '20 at 15:10

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