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CML2 Unmanaged Switch potential issue

Hi All,

 

I suspect unmanaged switch is causing connectivity issues - but I want to get your advice.

 

I have topology consisting of 10 CRS1000v, all connected to single unmanaged switch (via Gi1 on all of them). On the other side, unmanaged switch is connected to L2 switch (IOSvL2) via trunk interface. 

Issue

On L2 switch i created VLAN146, SVI for this vlan and gave it and ip address. 

On 3 routers i created Gi1.146 subinterface and gave them ip address from the same subnet. 

 

1. All 3 routers and L2 switch have correct routes in their respective routing tables. 

2. L2 switch SVI is up/up, STP for VLAN146 is present and forwarding. 

 

Still, I cannot ping anything in this subnet. I debugged ip packets, I will paste results below, but it seems like packets are sent just fine, but they never arrive to destination - between CSRs and L2 switch is only unmanaged switch.

 

Is it possible that this switch is somehow blocking traffic?

 

Thanks in advance. 

 

## debug from CSR1 - ping towards L2 switch

 

CSR1#ping 155.1.146.21
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 155.1.146.21, timeout is 2 seconds:

*Jun 5 13:21:49.890: IP: tableid=0, s=155.1.146.1 (local), d=155.1.146.21 (GigabitEthernet1.146), routed via FIB
*Jun 5 13:21:49.890: IP: s=155.1.146.1 (local), d=155.1.146.21 (GigabitEthernet1.146), len 100, sending.
*Jun 5 13:21:51.897: IP: tableid=0, s=155.1.146.1 (local), d=155.1.146.21 (GigabitEthernet1.146), routed via FIB
*Jun 5 13:21:51.897: IP: s=155.1.146.1 (local), d=155.1.146.21 (GigabitEthernet1.146), len 100, sending.
*Jun 5 13:21:53.896: IP: tableid=0, s=155.1.146.1 (local), d=155.1.146.21 (GigabitEthernet1.146), routed via FIB
*Jun 5 13:21:53.896: IP: s=155.1.146.1 (local), d=155.1.146.21 (GigabitEthernet1.146), len 100, sending.
*Jun 5 13:21:55.897: IP: tableid=0, s=155.1.146.1 (local), d=155.1.146.21 (GigabitEthernet1.146), routed via FIB
*Jun 5 13:21:55.897: IP: s=155.1.146.1 (local), d=155.1.146.21 (GigabitEthernet1.146), len 100, sending.
*Jun 5 13:21:57.912: IP: tableid=0, s=155.1.146.1 (local), d=155.1.146.21 (GigabitEthernet1.146), routed via FIB
*Jun 5 13:21:57.912: IP: s=155.1.146.1 (local), d=155.1.146.21 (GigabitEthernet1.146), len 100, sending.
Success rate is 0 percent (0/5)

2 REPLIES 2
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Beginner

Re: CML2 Unmanaged Switch potential issue

Hi, I was able to get the two devices to ping each other while using the following command on both routers:

 

int g1.146

encapsulation dot1Q 146 native

ip add 155.1.146.x 255.255.255.0

 

 

Highlighted
Beginner

Re: CML2 Unmanaged Switch potential issue

I may be misunderstanding, but I don't believe the unmanaged switch supports trunks meaning any tagged packets will be ignored.
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