Exceptionally knowledgeable and results-driven network engineer with 5 years experience in network design, administration, troubleshooting, and software/hardware modification with a solid track record of successfully managing multiple projects within deadline oriented, change-control environments and a proven talent for creating and implementing solutions to streamline operations and increase organizational efficiency united with cross-functional, cross technology experience in the design and delivery of network infrastructure development.
Exceptionally knowledgeable and results-driven network engineer with 5 years experience in network design, administration, troubleshooting, and software/hardware modification with a solid track record of successfully managing multiple projects within deadline oriented, change-control environments and a proven talent for creating and implementing solutions to stre
This was definetely a weird one for sure. Cisco TAC was unable to reproduce anomalies found on the production systems utilizing same hardware and IOS. Big bummer there, thought TAC could figure anything out.
They did however suggest we upgrade our IOS's on our 3750's to a current maintenance release due to the IOS we are running now is a deferred release. We went from 15.0(1)SE3 to 15.0(2)SE8. IOS upgrade went well and the issue was fixed with no other issues noted to date. I'd like to say the root cause was a bug in the IOS but since TAC couldn't find one its anyone's guess.
Hope this helps you out.
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Leo, Thanks for your input. UDLD is enabled to prevent any loops and to verify the health of the link. This is standard on any of our LAN templates and is configured without giving it any thought. UDLD recovery is configured as to allow the switch to try and recover if someone was to say bump one of the fiber pairs causing accidental loss of signal or a technician patches it in incorrectly. Saves us a lot of time too as this has happened on more than one occasion. I have disabled UDLD on both links and dot1q trunking was already enabled. This made no difference as the link on the distribution end still wouldn't connect. I will get rid of the error recovery commands and see if this makes any difference once I'm back in the office. Note that on my above statement (Ruled out bad access switch). This test switch was connected over a 1 meter fiber jumper so I could quickly test other ports/configurations. Only common thing I can see if all of this aside from udld being configured is that there is something wrong with the distribution switch but can't figure out what. Like I also stated there is also 5 other switches out there in 5 separate buildings displaying the same behaviour. Also note that when I had originally configured and installed these device, no more than a year or so ago, everything was working as advertised. Even with udld enabled. Dave
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I came across a serious issue the other day and have yet to find a workaround or solution when our access layer switch reloads. You'll see why this is such a serious issue by the last paragraph.
Typical network setup
Distribution switch:3750X-24S-S (15.0(1)SE3)
Access switch: 2960CG-8TC-L (15.0(2)SE)
Switches are connected by either SM or MM fiber and all links trunks (production and management traffic)
Up until here recently everything has been working normally, then due to maintenance being performed on our building electrical system our access layer switches loses power and reloads. Upon reboot the access layer switch will show a green light on the uplink port Gi0/9 or Gi0/10. Consoling into the access switch shows no cdp neighbors, no errors in the log, or any other indication that anything is wrong. However the uplink shows connected.
The distribution switch shows not connected to access switch. There was an error in the log indicating a udld on the link however the switch tries to recover from the error. However port never reconnects. Doing a show interface status the port shows notconnect not err-disable.
Ruled out the fiber as both strands were tested with no loss. Ruled out the SFP as there were several different ones tested on both ends. Set error disable recover time to 5 minutes; no change. Disabled udld on both ends; no change. Shut, no shut port, no change. Ruled out bad access switch; Connected test switch to port and test switch shows connected however no link on distribution switch. Tried to force an err-disable on distribution switch by looping fiber on SFP port and re-enabling udld. Port light never comes on and no indication that port is error disabling. Tried other open ports on the switch and after a couple a link is finally formed.
Currently running out of usable switchports and we are expecting another power outage next month. Also unable to open a TAC case as none of these are on maintenance which I had originally thought. We also have five other of the same model switches out there running the same IOS version. Three of these have experienced the same issue.
Anyone have any ideas, pointers or experienced this?
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Having troubles with all of my 2960S's with lanbase-routing enabled and 0 routed interfaces showing up in the template. I only have one SVI configured and that is the managment SVI 5 The current template is "lanbase-routing" template. The selected template optimizes the resources in the switch to support this level of features for 0 routed interfaces and 255 VLANs. Other problems occuring are not being able to reach my neighbor, a 3750X and vise-versa. Both can see each other with a show cdp neigh det but can't ping each others managment IP. Not exactly sure what is going on because I can hook the 2960S up to an older 3750 and I'm able to reach the managment interface of the 2960S. Almost makes me believe that there is something going on the 3750X, but the 0 routed interfaces on the 2960S is somewhat troubling. The 2960S is running IOS 15.0(2)SE and the 3750X is running IOS 15.0(1)SE3 I've changed some of the information in here for security purposes but wanted to give an output on what I'm seeing. 2960S1#sh cdp neigh det Device ID: 3750X1.xxx.com Entry address(es): IP address: 172.XX.X.X Platform: cisco WS-C3750X-24S, Capabilities: Router Switch IGMP Interface: GigabitEthernet1/0/26, Port ID (outgoing port): GigabitEthernet1/0/24 Holdtime : 120 sec Version : Cisco IOS Software, C3750E Software (C3750E-UNIVERSALK9-M), Version 15.0(1)SE3, RELEASE SOFTWARE (fc1) Technical Support: http://www.cisco.com/techsupport Copyright (c) 1986-2012 by Cisco Systems, Inc. Compiled Wed 30-May-12 13:41 by prod_rel_team advertisement version: 2 Protocol Hello: OUI=0x00000C, Protocol ID=0x0112; payload len=27, value=00000000FFFFFFFF010225020000000000006C2056173F00FF0000 VTP Management Domain: 'CISCO' Native VLAN: 5 Duplex: full Power Available TLV: Power request id: 0, Power management id: 1, Power available: 0, Power management level: -1 Management address(es): IP address: 172.XX.X.X 2960S1#sh ip arp Protocol Address Age (min) Hardware Addr Type Interface Internet 172.XX.X.X 3 6c20.5617.3f41 ARPA Vlan5 Internet 172.XX.X.X - 0cd9.9610.c841 ARPA Vlan5 << 3750X Neighbor ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 3750X1#sh cdp neigh det ------------------------- Device ID: 2960S1.xxx.com Entry address(es): IP address: 172.XX.X.X Platform: cisco WS-C2960S-24TS-L, Capabilities: Switch IGMP Interface: GigabitEthernet1/0/24, Port ID (outgoing port): GigabitEthernet1/0/26 Holdtime : 127 sec Version : Cisco IOS Software, C2960S Software (C2960S-UNIVERSALK9-M), Version 15.0(2)SE, RELEASE SOFTWARE (fc1) Technical Support: http://www.cisco.com/techsupport Copyright (c) 1986-2012 by Cisco Systems, Inc. Compiled Sat 28-Jul-12 00:42 by prod_rel_team advertisement version: 2 Protocol Hello: OUI=0x00000C, Protocol ID=0x0112; payload len=27, value=00000000FFFFFFFF010225010000000000000CD99610C800FF0000 VTP Management Domain: 'CISCO' Native VLAN: 5 Duplex: full Management address(es): IP address: 172.XX.X.X 3750X#ping 172.XX.X.X Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.XX.X.X , timeout is 2 seconds: ..... Success rate is 0 percent (0/5) 3750X1#sh ip arp Protocol Address Age (min) Hardware Addr Type Interface Internet 172.XX.X.X 82 6c20.5617.41c1 ARPA Vlan5 Internet 172.XX.X.X 214 0017.9590.4241 ARPA Vlan5 Internet 172.XX.X.X 103 6c20.5624.c441 ARPA Vlan5 Internet 172.XX.X.X - 6c20.5617.3f41 ARPA Vlan5 Internet 172.XX.X.X 105 fc99.47d3.bfc1 ARPA Vlan5 Internet 172.XX.X.X 0 Incomplete ARPA << 2960S Neighbor Internet 172.XX.X.X 142 fc99.479f.85c1 ARPA Vlan5 Othere strange happenings on other 2960S's is that when I do a sh cdp neigh det from my neighboring 3750X is that the management IP is showing up as the other SVI I have configured on the 2960S and not the SVI that I have setup for man I have reached out to TAC on this but it has been hit and miss getting into touch with the assigned engineer so if anyone has a clue on this please let me know. Thanks, Dave
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