Switching

Hello All,

I'm new to Juniper and need some assistance. Current situation, we are in the process of migrating our cisco infrastructure to Juniper. Our ex4300 will serve as our core switches. After some research, I was able to create a  IRB (server as management) with an ip address and link it to my L2 vlan. When I try ping internally on the switch, I'm getting no route to host.  With cisco, you didn't have to put routes in unless you were a downstream and that was a default gateway. 

Currently, trying to build out a lab network before the migration...just fyi, so I'm wide open to suggestions

Config Excerpt:

irb {
unit 4 {
family inet {
address 10.10.10.1/24;
}
}
}

vlans {
Management {
vlan-id 4;
l3-interface irb.4;
}
default {
vlan-id 1;
}

Error:

<username>@namet# run ping 10.10.10.1
PING 10.10.10.1 (10.10.10.1): 56 data bytes
ping: sendto: No route to host
ping: sendto: No route to host

there was a similar question in this forum yesterday

an IRB is only up when there is at least one active interface whith a corresponding vlan on the switch

so check your irb state  ( show interface irb ) and show vlan  for an active interfaces

regards

alexander

apologies, I'm not sure that I completely follow..but here is the output

user@host# run show interfaces irb
Physical interface: irb, Enabled, Physical link is Up
Interface index: 640, SNMP ifIndex: 501
Type: Ethernet, Link-level type: Ethernet, MTU: 1514
Device flags : Present Running
Interface flags: SNMP-Traps
Link type : Full-Duplex
Link flags : None
Current address: <removed>, Hardware address: <removed>
Last flapped : Never
Input packets : 0
Output packets: 0

Logical interface irb.4 (Index 599) (SNMP ifIndex 605)
Flags: Hardware-Down SNMP-Traps 0x0 Encapsulation: ENET2
Bandwidth: 1000mbps
Routing Instance: default-switch Bridging Domain: Management+4
Input packets : 0
Output packets: 0
Protocol inet, MTU: 1500
Flags: Sendbcast-pkt-to-re, Is-Primary
Addresses, Flags: Dest-route-down Is-Default Is-Preferred Is-Primary
Destination: 10.10.10/24, Local: 10.10.10.1, Broadcast: 10.10.10.255

user@host# run show vlans

Routing instance VLAN name Tag Interfaces
default-switch Management 4
ge-0/0/0.0

Again with the routing-instance.  You do NOT need a routing-instance to make this work.  I would delete the routing instance and get it to work first, and THEN create and add to the routing instance.  I assume the physical interface you are working with is ge-0/0/0.  It's family is Ethernet-Switching and you have some VLAN for which ge-0/0/0 is a member of the VLAN and then the IRB is associated with the VLAN?

So I can configured an access port and plugged a workstation. I can now ping the IRB interface from switch itself. 

I'm a little confused at this point. Since this is a virtual interface, I wouldn't expect to need to plug a workstation in and assign the interface. Can you provide a brief explanation? 

Perform a "show interface terse | match irb"

Unplug the workstation, and repeat the command.  Is IRB now up or down?  For IRB to be up some physical port associated with the IRB must be up.

Hi rccpgm,

When I unplugged the workstation, the irb went down after running the command you provided and I was no longer able to ping from the console. So I can see why it fails now.

To better understand, why is this? RVI doesn't need a physcial port to be up but irb does. Sorry if I'm asking alot... 

RVI (IRB) is associated with a L2 VLAN and [for any/all vendors] a VLAN is only up when some interface/port within the VLAN is up.  So with no interfaces active, VLAN is down and therefore corresponding RVI/IRB is down.

Thanks makes perfect sense! 

i cant ping to irb interface say is down, i associate to physical interface but not come up