ASR903 Connectivity Issue with daisy-chain switches

[RRR3]

Dear Friend,

Five switches of cisco (IE2000,IE3000,IE3300) have been daisy-chained and the first switch is connected to CISCO ASR903 router.

Each switch has got 5 Vlan's


The router to switch-5 ping is always ok

From switch-1 all other switches are reachable and vice-versa.

Issue Scenario 1:
The router can ping directly connected switch-1 sometimes not always
The router is not able to ping in between switches 3 and 4.

Issue Scenario 2:

The Router can ping all switches, but not devices connected to switch ports.
Any help would be highly appreciated.

Thank you
Ram

[balaji.bandi]

Daisy chain means, we expect all these layer 2 Extended, and most of the Layer config Located on ASR 903, Only Management VLAN SVI is configured on the Layer 2 switch for Management, this should work as expected technically.

So please post ASR config and IE device config was possible to look what is the issue here?

[RRR3]

Dear BB,

Thanks for the quick response. Yes. It's layer-2 extended.

Herewith, uploading the router and switch configurations.

Thank you

Rama

[Richard Burts]

I find this post a bit puzzling. The original post describes a network with ASR903 with switches daisy chained. The post says that the router can ping switches and switches can ping switches which sounds like the network is working. Then it describes 2 scenarios where things do not work. Did something change? If so then what changed?

We now have the config of the router and of one switch. Are these configs from the working state or from one of the not working scenarios?

It would help us understand the situation if there were a diagram showing the network topology (what connects to what).

It would be helpful if we could see the output of these commands on the switch

show cdp neighbor

show interface trunk

show ip route

show arp

I have looked at the posted configs and do have several comments and questions:

- the switch is configured with 2 interfaces as trunks. Would we be correct to assume that one connects to the router and the other connects to the neighbor daisy chained switch?

- the switch has multiple vlans configured with access ports assigned to some of the ports.

- The switch has 1 vlan interface with an IP address (vlan 510). There are no access ports in this vlan (which might be appropriate if this vlan is only for management of the switch). It is in the state of up/down. We need to investigate why it is not up/up.

- the router config is quite complicated. It has many VRFs, many BDI interfaces, runs both OSPF and BGP. We probably should concentrate on the parts that deal with connection to the switches.

- the router configuration has 2 port channels. Would we be correct to assume that these port channels connect to the daisy chained switches?

- I am puzzled that the IP addresses configured on the port channel (10.10.1.33&37) do not match up with addressing on the switches. Can you provide clarification about this?

- the configuration runs OSPF on PO58 but no on PO9. Is that intentional?

- the configuration of OSPF has a network statement for 10.10.1.0 but the mask used does not seem to match anything on the router. Is that intentional?

- the configuration has 6 BDI interfaces configured with the same IP address which is in the subnet used by vlan 510 on the switch. I am not clear how the single vlan on the switch communicates with 6 BDI/VRF on the router. 

[RRR3]

I find this post a bit puzzling. The original post describes a network with ASR903 with switches daisy chained. The post says that the router can ping switches and switches can ping switches which sounds like the network is working. Then it describes 2 scenarios where things do not work. Did something change? If so then what changed?

Ans: This is a fresh configuration

We now have the config of the router and of one switch. Are these configs from the working state or from one of the not working scenarios?

Ans: Yes these are in working state.

- the switch is configured with 2 interfaces as trunks. Would we be correct to assume that one connects to the router and the other connects to the neighbor daisy chained switch?

Ans: yes. One trunk port is from router and other trunk port is connected to neighbouring switch.

- the switch has multiple vlans configured with access ports assigned to some of the ports.

Ans: Only vlans required is assigned to ports as of now. In future when more devices are connected the remaining vlans will be used.

- The switch has 1 vlan interface with an IP address (vlan 510). There are no access ports in this vlan (which might be appropriate if this vlan is only for management of the switch). It is in the state of up/down. We need to investigate why it is not up/up.

Ans: Yes. This is just for the management of the switch. The SVI is UP.

- the router config is quite complicated. It has many VRFs, many BDI interfaces, runs both OSPF and BGP. We probably should concentrate on the parts that deal with connection to the switches.

Ans: OSPF and BGP are for the L3 mpls traffic. This is not in connection with the switches.

- the router configuration has 2 port channels. Would we be correct to assume that these port channels connect to the daisy chained switches?

Ans: No. These Port channels are for different purpose. These are used for L3 mpls traffic. This is not in connection with the switches. These port channels will get connected to other routers.

- I am puzzled that the IP addresses configured on the port channel (10.10.1.33&37) do not match up with addressing on the switches. Can you provide clarification about this?

Ans: The port channels are used for L3 mpls traffic. This is not in connection with the switches.

- the configuration runs OSPF on PO58 but no on PO9. Is that intentional?

Ans: Yes. This is for L3 mpls traffic. This will be configured in later stage.

- the configuration of OSPF has a network statement for 10.10.1.0 but the mask used does not seem to match anything on the router. Is that intentional?

Ans: This is by mistake. We will remove this statement.

- the configuration has 6 BDI interfaces configured with the same IP address which is in the subnet used by vlan 510 on the switch. I am not clear how the single vlan on the switch communicates with 6 BDI/VRF on the router.

Ans: Its port wise configuration. Each port is defined with 15 service instances each poping out a particular VLAN and forwarding to a particular BDI.

For eg. port gi0/0/0  is incharge of BDIs from 100 to 115. Port gi0/0/1 is incharge of BDI 200 - 215.

Each port is assigned/alloted a unique VRF. hence BDI 100-115 will be in one VRF and BDI 200-215 will be in a different VRF.

One set of daisy chained switches will be connected to only one port ie gi0/0/0. Hence only BDIs from 110-115 is incharge for the partcular set of switches and its corresponding devices attached to each switch.

Another set of daisy chained switches will be connected to port gi0/0/1. So BDIs from 201-215 will handle the traffic from this port. and so on.

Currently there is a fiber cut between router and first switch. I will upload the configuration along with cdp neighbors and arp table once we get back online.  

[Richard Burts]

Rama

Thanks for the additional information and for addressing my comments/questions. I note that your diagram shows that the router connects to the switches on Gi0/0/6. But when I look at the posted router config that interface is not configured (no IP address, no vlan subinterfaces, or anything). I look forward to the outputs when you get back online.

[RRR3]

Hi 

Attaching current running configurations of switches and router

regards

Ram

[balaji.bandi]

The router to switch-5 ping is always ok

what is the switch 5 IP address where is the config ? did the switch has default-gateway - 172.16.8.1?

From switch-1 all other switches are reachable and vice-versa.

what is the IP address of other switches, hope all belong to VLAN 510(i am guessing) - it would be nice all switch config here .

ssue Scenario 1:
The router can ping directly connected switch-1 sometimes not always
The router is not able to ping in between switches 3 and 4.

what is the switch 3 and 4 IP address, it would be nice to have some network digram and explain what port connected where ?

router only 1 port connected to daisy chain ? so what port its connected ? what switch ?

Issue Scenario 2:

The Router can ping all switches, but not devices connected to switch ports.
Any help would be highly appreciated.

Not make any sense? on the above, you mentioned you only ping switch 1 not rest (or 3 and 4).

how many switches in daisy chain.

end devise in what Lan? what is the IP address of end device ? what Gateway it was configured ?

[RRR3]

Hi BB,

what is the IP address of other switches, hope all belong to VLAN 510(i am guessing) - it would be nice all switch config here .

 Answer: All switches are in same vlan ie 510.

what is the switch 3 and 4 IP address, it would be nice to have some network digram and explain what port connected where ?

 Answer:

router only 1 port connected to daisy chain ? so what port its connected ? what switch ?

 Answer: Attached diagram with IP address of switches.

how many switches in daisy chain.

 Answer: Currently running with 5 swithes

end devise in what Lan? what is the IP address of end device ? what Gateway it was configured ?

Answer: We have configured vlan 500 & 501 in  ports of the switches.

Gateway for device in vlan 500 is 172.16.3.1

Gateway for device in vlan 501 is 172.16.24.1

All gateways are defined in ASR Router.  

Due to fiber cut between router and first switch we are not getting access to switches. I will upload all switch configurations once we get back those devices online.

Attaching configuration running in router.

Only concerned part is port number gi0/0/6 and BDIs from 700-715

Thanks

Ram

[Richard Burts]

Ram

Thanks for the response. Until connectivity to the switches is restored and we can see the additional outputs I do not believe there is much that we can do. Please let us know when access to switches is available.

[balaji.bandi]

Thank for the information, You have configured HSRP configuration, do you have other Router in the network ?

good to have switch configuration to map correctly see where it was broken ?

[RRR3]

Hi BB

Attaching all configurations.

Yes we are running HSRP. The secondary router is not active right now. Only One router is in place which is having the highest priority.

Regards

Ram

[Georg Pauwen]

Hello,

your switches need:

--> ip default-gateway 172.16.9.253

Since BDI110 is in a vrf: you probably need to put Vlan 510 on the switches in that vrf as well

interface BDI110
ip vrf forwarding acc019
ip address 172.16.9.253 255.255.254.0

you probably need to put Vlan 510 on the switches in that vrf as well:

interface Vlan510

--> ip vrf forwarding acc019
ip address 172.16.9.215 255.255.254.0

Not sure if that can be configured on the switches though, if not, take the management Vlan out of the vrf on all devices.