C9300 configuration issues

[Artezys79]

Hi All,

I have replaced my Meraki switch with Cisco C9300 and replicated exactly same configuration which is proven to be working on meraki device including wireless AP, however once I switch with C9300 no DNS relies coming from google DNS onto switch or wireless AP, and I am unable to ping external dns. From the C9000 IP address all works fine, I can ping external dns but not from any othe vlans, where two of them belongs to wireless AP.

Would appreciate for an advise of trouble shooting steps. Routing, Catalyst Switch

[Flavio Miranda]

@Artezys79 

Do you have ip donain-lookup on the switch?

 Are the clients receiving the DNS server through the DHCP?

[balaji.bandi]

From the C9000 IP address all works fine, I can ping external dns but not from any othe vlans, where two of them belongs to wireless AP.

I take this as from switch you able to ping all ok to external.

We need to know how is other VLAN Routing and can you provide some examples

troubleshooting :

1. show ip route (check you have routing works as expected) - is this static routing ?

2. ping and Traceroute using source interface of the vlan not working ?

3. what is the VLAN IP address - is this coming from DHCP ? what DNS that using  ?

4. how is your network looks like - you replaced the switch, what other device in the path to reach internet ?

5. where is the Other VLAN IP address gateway residing in switch ?

6. may be check on the up side device have any arp and try to clear ARP for old IP if any ?

[Artezys79]

Please find my comments below:

1. show ip route (check you have routing works as expected) - is this static routing ?- Yes, I have setup default route with static IP belonging to the VLAN on FPR 1120.

2. ping and Traceroute using source interface of the vlan not working ? - traceroute doesn't show anything at all, but I can ping everything from switch IP, which is L3 interface.

3. what is the VLAN IP address - is this coming from DHCP ? what DNS that using ? - no DHCP, gateway on FPR 1120 set with .1/29 and VLAN 35 on the switch set for .2/29.

4. how is your network looks like - you replaced the switch, what other device in the path to reach internet ? - with merakiswitch replaced I have left with merak AP, which I am trying to migrate onto C9300. In this particular case AP receiving data from Meraki Cloud but no DNS responses when connected to C9300.

5. where is the Other VLAN IP address gateway residing in switch ? - on the FPR 1120 subinterface

6. may be check on the up side device have any arp and try to clear ARP for old IP if any ? - this step hasn't been actioned. I will try to clear ARP on the FPR 1120.

P.S Is there any particular config required for uplink setup? As My deafult route pointing to the FPR 1120 address but not sure if this is sufficient.

Thanks

[balaji.bandi]

as per information looks simple setup, but like to see below config from switch (remove any confidential information)

show run

show ip route

show ip interface brief

you have not addressed some questions as asked before please clarify :

1. from switch all working (what is switch IP)

2. from client IP nothing working  (what is IP address, is this same IP of switch ?)

[Artezys79]

Please find attacehd config.

Switch IP is 10.66.102.2 (it is a management IP, so not sure if it is deemed as switch IP).

It is an uplink address from the logs attached.

After arp clearance, I am able to ping 8.8.8.8 from VLAN's 1515 and 2020, which belongs to DHCP and wirelss AP, however on the wireless AP there is an issue with DNS, all down and wonder if something must be done at switch level, like name resolution.  

[balaji.bandi]

VLAN's 1515 and 2020, which belongs to DHCP and wirelss AP,

can you clarify what is the mean of DHC and Wireless AP ? what is the means of WIFI and WIFI-S

however on the wireless AP there is an issue with DNS, all down and wonder if something must be done at switch level, like name resolution.  

This was not clear to me that - the AP (means client or AP it self), is this only issue with WIFI or AP ?

If the Clients not able browse - then from client post out put from below :

traceroute 8.8.8.8

ping 8.8.8.8

ipconfig /all

nslookup cisco.com

[Artezys79]

I have configured dhcp server on c9300 and wireless access point leases ip addresses from switch dhcp. WIFI and WIFI-S are two different wireless SSID's which I use for defferent deviceson wireless connection.

From the client I am unable to do trace route, ping to 8.8.8.8 or nslookup.

WIFI-S reside on the VLAN 2020 and I am able to ping from the switch 8.8.8.8, but from the clients on the same network not, and only able to ping uplink's IP on the switch side and not on the router side.

[MHM Cisco World · Accepted solution]

please check below points 

1- remove the domain name google.com , you dont have this domain  

2- this IP 175.35.69.1 which I think your ISP IP?
if Yes then you need to do NAT for traffic 

3-run ""ip routing"" in SW

MHM

[Artezys79]

Thank you for your suggestion.

Issue was with ip routing being disabled, after enabling it routing started to work as expected.

[balaji.bandi]

Ok what is Meraki Switch model  - are you using the same IP address of Meraki switch IP when you replacing with Cat 9K switch ? (may required clera arp on the uplink side routers, since the switch MAC address changed) - no idea (until we know what is that device)

I suspect here uplink side not doing routing or NAT not happening on the LAN side IP 

Since switch has the IP have routing and NAT work only specific IP range ?

Do you have access on the device switch connected ? what devices is that ? (can you check any routing and NAt required there)

Cat 9300 do support NAT example below if you like to pursue :

https://www.cisco.com/c/en/us/support/docs/switches/catalyst-9300-series-switches/217419-configure-and-verify-nat-on-catalyst-900.html

[Artezys79]

Thank you for your support, it was helpful to clear ARP table.