Welcome to the Cisco Community Ask Me Anything conversation. Submit your questions from Monday, February 2, 2026, through Friday, February 20, 2026. Our colleagues Amruta Navadagi, Anaya Kalawat, and Mohammad Mehtabuddin will be waiting to assist you...
Hi Folks,Problem here. We have building management systems (temparature guages etc) with devices on one subnet and I suspect they are not connecting to their server correctly.I think they use broadcast and unfortunately the server is on another subne...
I'm really confused about software and hardware cef. Here is an extract from the study material from cisco "A router with Cisco Express Forwarding enabled uses information from tables that are built by the CPU, such as the routing table and the ARP t...
PXE boot (WDS) stopped working after we upgraded MS switches to 18.1.9.The PXE client downloads the NBP, then hangs at "Contacting server" (0x102).- Same PXE failure on 3 different MS210 stacks in 3 different networks, all on 18.1.9.- Downgrading one...
Situation:endpoint on 10.3.0.5 is ARPing for endpoint on 10.22.0.222. 10.3.0.5 encapsulates it w/ target L2VNI in configured G. Frame reaches to spine & gets no forwarding to another local-site leaf. Intersite on IR works perfectly. As well there are...
I bought a Cisco Catalyst switch from a hamfest (amateur radio swap meet) and am trying to get it working. I am a retired software engineer and am just looking to get this working. I can connect to it through a serial conection and can run some ini...
i have a 3850 stack of 2 switches in my mdf. i have another switch in my idf connected by fiber. everything has been good for years. i just added another 3850 switch into my stack in my mdf. now i cant access by idf switch at all. cant ping or p...
Hi ,We have SGT capable devices such as Meraki MR , Meraki MX , and Access switches. However , our core ( Arista ) is not SGT capable ( haven't tested but doesn't look capable ).I have read some blogs and articles about SXP but I'm fairly new to all ...
I am looking for a feature/command on Nexus 9K device. The requirement is to drop mcast packets on trunk ports on a certain vlan but only on certain trunk ports. For example Port 1 and 2 is a trunk port each carrying vlan 100 and 200. I want to blo...
Hi ,We would like to confirm the maximum supported number of copper RJ-45 SFP transceivers on the Cisco Catalyst C9550-48L4CD.For GLC-TE (1G RJ-45), what is the maximum number of transceivers that can be installed simultaneously?For SFP-10G-T-X (10G ...
Hi,I performed an ISSU upgrade on the Catalyst 9500-40X switches from IOS-XE 17.15.6 to 17.18.4. During the upgrade, I observed traffic interruption and ping drops for approximately 15–20 seconds, despite NSF and SSO being enabled.Is this expected be...
Hi guys,I'm running a Cisco WS-C3850-12X48U, I've just tried to add a C3850-NM-8-10G module (previously blank) to it but it seems it's not detected rejected.Nothing in console when adding/removing the module, links aren't going up.How to be sure the ...
Hello,I installed a new router and trying to backup the initial configuration to our tftp server. But getting the error " %Error opening tftp://172.17.0.39/corporate-confg (Timed out)"I can ping the tftp server from router. There is no firewall in be...
I am trying to troubleshoot/investigate this issue and it does not seem to be making any sense to me.I have a Nexus C9300-48U version (Version 17.9.2r CAT9K_IOSXE). The switch is configured to talk to 3 Cisco ISE PSN nodes, node1, node2, and node3 (...
hi all,is there a command to run to detect if i have duplicate ips on a vlanthanks,rob
I have a C9500-48Y4C IOS XE 17.12.4 that is notifying of a lot of MAC flapping. This is the typical error log. Oct 27 13:14:41.253: %SW_MATM-4-MACFLAP_NOTIF: Host 0050.56b1.96a0 in vlan 412 is flapping between port Twe1/0/3 and port Po1When the switc...
