Switching

I think some posts on this forum touched on the topic but may be more complicated setups than mine.  I have a EX8208 with two SRE, therefore two management ports.  The config is shared between both, so both management ports try to use the same me0 IP and there is an IP conflict.  Accordingly, remote connections to that IP flip between the RE and BK making it rather useless.  If I disable one of the management links or unplug the cable, an alarm starts about a management port being down.  I currently have it set to ignore the alarm and I only have one connection live at a time, but this isn't ideal or sensible.  I've found no official documentation about how to resolve this conflict; JunOS wants both ports to be up, but creates an IP conflict if you do.

Without an XRE200 and only a single 8208 with two SRE, is there an appropriate solution internal to the 8208?  Do I need to resort to trying to set two IPs and try to externally filter traffic so they do not fight?  I wish it just had a vme 🙂 Thanks.

Hi,

If you have two SRE one of them should serve as master and the other should be backup.

You may see this documentation to understand more about SRE on EX8208:

http://www.juniper.net/techpubs/en_US/release-independent/junos/topics/reference/specifications/sre-module-ex8208.html

You may also configure redundancy on both SRE:

http://www.juniper.net/techpubs/en_US/release-independent/junos/topics/concept/ex8208-component-and-functionality-redundancy.html#jd0e81

Based on my experience, I configure me0 management IP with different addresses.

They are already configured as master and backup, that part works out of the box, but when I "set interfaces me0 unit 0 family inet address 10.1.1.2/24" BOTH sre modules respond to that same IP.  How do I "configure me0 management IP with different addresses"?  An example command would be helpful.  Thanks.

Hi,

Do you implement your EX8208 as member of Virtual Chassis?

I hope this document will help you:

This are Best Practice Guidelines for deploying  EX8200 

VIrtual Chassis Configuration

http://www.juniper.net/us/en/local/pdf/implementation-guides/8010081-en.pdf

No I do not have a Virtual Chassis for the EX8208.  That would require an XRE200 which I do not have, and I do not have a second EX8208.  I am however familiar with VC.

Here you go; looks like Apply Groups is needed, similar to SRX

http://kb.juniper.net/InfoCenter/index?page=content&id=KB15687

But I think you want the same address on both, yes? If so, I think the answer is no. How do you manage the box with network monitoring and or backups? I've usually used the VRRP float address for that purpose.  You could probably use a Loopback too..

Thanks! Two IPs should be fine since I'll know exactly which SRE I'm logging into and they won't conflict. I've applied this change and so far so good.  I vaguely recall reading about using groups in this manner for different re's but it has been a while.  I've seen other posts mention apply groups but they didn't contain enough specifics.

You can also set the hostname inside the apply-group so the prompt is different on each RE.  For example:

set groups re0 system host-name lab-ex8208-1.re0
set groups re1 system host-name lab-ex8208-1.re1

If you do that though, you need to delete the host-name from the main configuration section.  If you don't, the explicit setting overrides the apply-group inheritance.

Also, you can configure it to not generate a system alarm if the management link is down:

set chassis alarm management-ethernet link-down ignore

Cheers!

-Chad