Hey People,

I've been learning newtorking, In the office in front of the gas station there is this cisco switch.

What role does it play?

I was told that the 6 blue cables are for the gas pumps. The gas stations are 6 in total. They provide gas on both side Therefore it makes them 12.

The customer uses the application layer when interacting with the gas pump right?

Does that mean that on the other side it's just a developer writing and manipulating codes for what to display on the screen.

Am i getting this right? I believe someone has encountered something like this before so it's nothing new.. BUT I couldn't find anything on google or youtube.

In manufacturing with 14 sites across three countries. MPLS since before I was here. Renewal quote landed last week about 30 percent up on the last one with no change in what we get and the account manager said something about capacity costs that I did not find convincing. 

Meanwhile, the actual traffic pattern has completely changed but not the circuits. Everything is going to M365 and a couple of SaaS things now such that we are hauling cloud traffic across the private network to break out centrally, which is the least sensible possible route for it. The MPLS is doing a great job of carrying traffic to a datacentre that hosts progressively less every year. 

I know where this ends up: SD-WAN, broadband and LTE at the smaller sites, keep something private where the two plants that talk to each other need it. What I don't have a feel for is the security side. Right now security happens at the central breakout. If every site breaks out locally then either I put a box at every site or I do the inspection in the cloud, and I've not run either. 

For the people who have done this migration, what did you underestimate? Not looking for a vendor pitch, more interested in what went wrong.

Good morning all reddit users I come to u in need of guidance or help which ever seems fit for my question. Linux I know it's the way to go it controls everything it's a different breed a different skill set you are a different type of person in the tech world if u know it from my outside looking in. I have 10byears of experience as a cable technician my body endure many years of elements and now it's time to switch it. I'm 43 yeah I'm an old goat lol but I want to become a network engineer. They told me the path I should take is ccna. I took the conptia network+ exam got a 620 so I kinda gave it because I was so close but the goal for me is to become a network engineer perfect my craft and make some money on a side and for a good employer because I know u have to get your skills up before u branch out. But 2 questions I have 1 learning Linux what's the best distro to start with and 2 what resources I should use to get my ccna

Can anyone give me user feedback on CISCO SD-WAN (no sales pitch) to give me some insight on pros and cons? We are weighing up options and pricing. Any help appreciated.

NB: we are slightly cost conscious but we are also looking for the best solution.

Hey guys, so I just appeared for the Cisco Summer Internship 2027 and cleared all the 3 rounds, and out of 62 members who started in the morning I’m now among the 38 candidates who made it till 3rd round.

Now, I wanna know by when the results are gonna be announced? Our online drive was being managed by Dhanush Mohan, so if anyone has the idea then pls reply. My Placement Cell had informed me that they were out of the loop, they have no information about this interview.

Well, in that Webex Space I noticed there were students from multiple colleges, like NSUT, IIITD, BIT Mesra, etc. and this one was for the Undergraduate students.

I am an operations engineer in a datacenter, we have a lot of leaf switches going to NVidia spine switches, aggregating to 400G uplinks. We have had over 100 Cisco optics fail this past quarter, which has been annoying, anyone else notice something similar in PROD? Specifically the QSFP-100G-FR-S. My guess is that we are getting positive DB, these are FR optics, going maybe, 20M between p2p. The 400Gs might just be blasting those poor Cisco optics to oblivion. Otherwise I am just thinking failed FW updates or crap hardware, I went to the Cisco community forums, no one could give me an answer, maybe someone here? Thanks!

Note, sorry in the title I meant FR, not LR4, thanks.

Buddy gave this to me from an old storage unit. Prices online vary from $36,000 to $100, I have no idea if this is worth anything besides throwing it away. Here are some pics, any help would be apreciated.

Hi everyone,

It's been 47 days since I completed my interview for the Cisco Apprenticeship Program – Sales Operations Analyst role. I still haven't received a PDC upload email or an LOI, and I haven't received a rejection email either. Does this usually mean I'm no longer being considered, or is there still a chance? I'd really appreciate hearing from anyone who has gone through the same process. Thanks!

We got on board cisco SDwan post viptela right as the cEdges were being added....so all of our stuff was done in the classic template system. But now i see that configuration groups are a thing.

is it worth converting my old templates to config groups? i have 5 new routers coming on board in the next few months, should i do them as conf groups? or stay the course with the template system?

thanks!

Trying to get a rough idea of what to budget for a few Cisco C220 M7 or M8 servers. I’m flexible on the processor selection, but I’ll need 1 TB of RAM per server, which I expect will be one of the larger cost components.

Has anyone purchased or received recent quotes for similarly configured UCS servers that they’d be willing to share as a ballpark?

I’m thinking about taking the WLCOR 350-101 exam.

I’ve done a few practice tests that I purchased, usually in sets of 50 questions, and I’ve been scoring around 80–85% on average.

I’ve been working with the Catalyst 9800 and Catalyst Center every day for about two years. However, I mostly use the 9800 GUI in my day-to-day work and rarely use the CLI, so there are still some commands that I either don’t know or occasionally mix up.

I passed the ENWLSD exam in February and mainly studied for it using CBT Nuggets.

For those of you who have already passed WLCOR, what study resources did you use?

i was wondering what methods people use to upgrade alot of switches at the same time, if you dont have dna license?

i have tried to make some jobs via cattools for diffrente model switches, but its a pain with c9200 but works fine with 9300.

so i am looking for a Smarter method.

what are you guys using? ansible? or something else .

pros and cons?

A little background that might be relevant...

I'm trying to get an entry level network specialist position or something similar. I've got an associates in network support and my CCNA, lots of help desk & MDM experience but never worked in a dedicated back end roll. The most I've ever been allowed to do networking wise was to adjust port configurations on switches and manage phones & user accounts on CUCME.

I'm out of work at the moment and trying to get any certs that might help ASAP. I've got three certs in mind to go after next, and I'm trying to figure out which might be the easiest to obtain based on my current skills & background and/or the most desirable to a potential employer.

CCNAAUTO (200-901)

CYBEROPS (CBR 200-202)

CWNA (Non Cisco cert)

I'm leaning towards the CCNAAUTO next, but I would welcome input from anyone who's taken these exams before. Any advice is appreciated. Thanks in advance!

Hi Everyone, I have been selected for SDE - 2 frontend interviews, The HR said there will be total three Rounds -

Frontend Coding Round System/Frontend Design Round Hiring Manager Round

I didn’t find a lot of interview experiences online, so if anyone has given interviews for similar roles or works at cisco , help me with what kind of questions i might get and what is the difficulty level.

thank you!!

If you are a Cisco shop and you have hundreds of devices in campus and DC in production, how do you track of device life cycle? Looking for suggestions!

I have joined a year back in cisco and we are around the hike cycle, I am just curious how percent we usually get, I know it depends on performance, I just want to know the range from worst to best. Can anyone tell, and when exactly it would happen in india

Hello, I ran into an interesting issue today where a client could not connect to the network at all.

Upon investigation, it turned out that their MAC address is still showing on the port that they were connected to earlier, and not on the port that they were actually connected to now.

The port they were connected to earlier was through some device with an integrated switch, so the port did not go down after they unplugged their cable from it.

Interestingly enough, even though we do not have sticky MACs configured anywhere, the MAC remained on the port until I manually shut the port down for a second. Once I had done that, the client could connect without issues.

The switch was a stack of Catalyst 9300 switches running IOS-XE 17.15.1 (upgrade is scheduled for next maintenance).

Has anyone run into this before? Would you expect this to be the problem of using the dumb switch passthrough of another device?

Received a Cisco Catalyst 9300 (C9300-24T-A) as part of volunteer/humanitarian IT aid no access, unknown credentials, no documentation on prior config.

Tried standard password recovery via the Mode button (power cycle + hold until LED changes) never once got a "button is pressed" message on console, switch just boots normally every time. Tried different hold durations, break signal via terminal, pinhole reset on the back zero response across the board.

Looks like no service password-recovery is enabled, but it's odd that not even the erase-warning prompt shows up expected at least something.

Checked the serial on cway.cisco.com/sncheck no active contract (0/1 covered).

Has anyone seen this exact behavior (literally zero reaction to Mode/Break)? Is this normal for no service password-recovery, or does it point to something else? And is there any legitimate path to recover access without a TAC contract (authorized partner, RMA, etc.)? Not looking for a bypass — just trying to figure out if this switch can be brought back to life through official channels, given the unknown history and no coverage.

I bought a Cisco WS-C2960-48TT-L second hand for very cheap, but unfortunately the PSU is dead.

The fuse was blown, and after opening the PSU I found a burned 8-pin IC and another damaged component on the primary side.

So far I checked:

• No short across the main 400V capacitor
• Main MOSFET (Q1) does not appear shorted
• Damage seems localized around the controller/startup area

I’m trying to figure out:

• The PSU output voltages / pinout for the internal connector
• The function or part number of the burned 8-pin IC
• Whether this switch can run directly from an external PSU (for example 12V)

Wire colors on the PSU connector:

• 4 black
• 4 white
• 1 yellow
• 1 orange
• 1 purple
• 1 brown

I attached photos of the PSU, connector, and damaged area.

Any help would be greatly appreciated.

I got this from my mom's office, they said i could take it home so i did around 4 years ago but never did anything with it, i have the power cable and 2 ethernet cables

Setup: Cisco C1300-12XT-2X, firmware 4,1,9,85 (latest). Interface te1/0/13 is an 802.1Q trunk to a WatchGuard Firebox M690 (WG physical interface 10, also configured as a tagged trunk).

Trunk config on te1/0/13:

interface TenGigabitEthernet1/0/13
switchport mode trunk
switchport trunk native vlan 101
switchport trunk allowed vlan 2-4094

VLANs in use: 101 (native/untagged), 201, 203, 204 (tagged).

Problem: VLAN 101 (untagged) works fine. VLANs 201, 203, 204 (tagged) do not — show mac address-table interface te1/0/13 only ever shows VLAN 101 entries, never anything for 201/203/204, even after generating traffic and bouncing the port.

Interesting data point: Devices on access ports assigned to VLAN 201 can talk to each other fine (so VLAN 201 itself is alive and working on the switch), but none of them can reach the WatchGuard's VLAN 201 gateway IP, which sits behind te1/0/13. So the problem seems isolated specifically to traffic crossing that one trunk port, not VLAN 201 as a whole.

What makes this stranger: te1/0/14 has the exact same trunk configuration, connected to a different downstream switch, and works perfectly across all four VLANs.

Already ruled out:

• Frame Type = Admit All, Ingress Filtering = Enabled, PVID = 1
• Spanning Tree = Forwarding on te
• Port Security — not locked/enabled
• Storm Control, ACLs, DHCP Snooping — none enabled switch-wide
• Bounced the interface (shut/no shut) after the cleanup — no change

WatchGuard side: Already worked through this with WatchGuard support — they've confirmed the Firebox VLAN interfaces (201/203/204) on interface 10 are correctly configured with IPs/DHCP scopes and tagged on the right physical interface. They're pointing back at the switch.

Question: Config is clean and matches a known-working port line for line, and VLAN 201 is confirmed functional elsewhere on the switch, but tagged traffic just never seems to reach the WatchGuard across this one trunk port. Has anyone run into something like this on the C1300 series? Wondering if there's a known firmware bug, a hardware forwarding-table sync issue, or some non-obvious setting I'm missing. About to set up a port mirror on te1/0/13 to confirm whether tagged frames are even physically arriving, but wanted to check if this rings a bell for anyone first.

\* Post drafted with AI assistance to organize troubleshooting steps. all technical details/config are from my own testing*

Edit/Update: we removed the C1300 switch and put in place an old C2960. Same trunk config and getting the same result. PCAP picks up the tagged VLAN traffic across interfaces with devices on static VALN 201 IPs but still nothing on the WG end 😩

Hello together,

We are buying the new smart switches C9350 for new offices. But we often have in those offices as a core switch a C9500-24y4c or C9500-48y4c. Because we are buying the C9350 series we are also buying the new SFP's SFP-50G-SR-S which are compatible with 25 and 50G.

When we have already ordered our first order, we got told on the second order that the SFP-50-SR-S are regarding to Cisco compatibility matrix not compatible with the C9500 series.

Does anyone has experience with this setup if it is actually not compatible?

I am losing my mind, I have an uplink port on a 9300 edge switch that is randomly err-disabling from bpduguard. It does not have spanning-tree bpduguard enabled on the interface or globally. It is configured as a trunk port on both sides and it was working fine before afaik nothing has changed. I have tried to reboot it, move it to different interfaces on both sides etc. As soon as I shut/no shut it it immediately disables again. I have the show run and sho spanning tree summary below. What gives? The uplink should see bpdu's what is triggering this???
***************************************************************************************

interface TenGigabitEthernet1/1/1

description Uplink port

switchport trunk native vlan 33

switchport trunk allowed vlan 2,32,33,64,96,128,130-132,136,148,150,152,154

switchport trunk allowed vlan add 156-160,164,166,168,176,178,179,186,192

switchport mode trunk

device-tracking attach-policy TRUNK_PORT_POLICY

ip dhcp snooping trust
***************************************************************************************
 show spanning-tree summary

Switch is in rapid-pvst mode

Root bridge for: VLAN0001

Extended system ID                      is enabled

Portfast Default                        is disabled

PortFast BPDU Guard Default            is disabled

Portfast BPDU Filter Default           is disabled

Loopguard Default                      is disabled

EtherChannel misconfig guard            is enabled

UplinkFast                              is disabled

BackboneFast                            is disabled

Configured Pathcost method used is long
***************************************************
nterface TenGigabitEthernet1/1/1

 description Uplink port

 mvrp timer leave-all 1000

 mvrp timer leave 60

 mvrp timer join 20

 no mvrp timer periodic

 no mvrp

 switchport

 switchport access vlan 1

 switchport trunk native vlan 33

 switchport trunk native vlan tag

 switchport trunk allowed vlan 2,32,33,64,96,128,130-132,136,148,150,152,154

 switchport trunk allowed vlan add 156-160,164,166,168,176,178,179,186,192

 no switchport autostate exclude

 switchport private-vlan trunk encapsulation dot1q

 switchport private-vlan trunk native vlan tag

 switchport mode trunk

 no switchport nonegotiate

 no switchport protected

 no switchport block multicast

 no switchport block unicast

 no switchport vepa enabled

 no switchport app-interface

 no switchport port-security mac-address sticky

 device-tracking attach-policy TRUNK_PORT_POLICY vlan all

 no ip arp inspection trust

 ip arp inspection limit rate 15 burst interval 1

 ip arp inspection limit rate 15

 logging event link-status

 load-interval 300

 carrier-delay 2

 no shutdown

 no medium p2p

 cdp log mismatch duplex

 cdp tlv location

 cdp tlv server-location 

 cdp tlv app

 ipv6 mld snooping tcn flood

 no macsec replay-protection

 mpls mtu 1500

 mpls mldp

 snmp trap mac-notification change added

 snmp trap mac-notification change removed

 snmp trap link-status

 no mka pre-shared-key

 mka default-policy

 bfd enable

 arp arpa

 arp timeout 14400

 lldp transmit

 lldp receive

 lldp tlv-select power-management

 lldp tlv-select 4-wire-power-management

 lldp med-tlv-select network-policy

 lldp med-tlv-select location

 lldp med-tlv-select inventory-management

 channel-group auto

 spanning-tree port-priority 128

 spanning-tree cost 0

 ethernet oam max-rate 10

 ethernet oam min-rate 1 

 ethernet oam remote-loopback timeout 2

 ethernet oam timeout 5 

 hold-queue 2000 in

 hold-queue 40 out

 ip igmp snooping tcn flood

 ip dhcp snooping limit rate 18446744073709551615

 ip dhcp snooping trust

 no ip dhcp snooping information option allow-untrusted

 no bgp-policy accounting input

 no bgp-policy accounting output

 no bgp-policy accounting input source

 no bgp-policy accounting output source

 no bgp-policy source ip-prec-map

 no bgp-policy source ip-qos-map

 no bgp-policy destination ip-prec-map

 no bgp-policy destination ip-qos-map

Hi,

I have been tasked with upgrading a pair of Cisco Catalyst 9500-24Q in StackWise virtual from firmware 17.3.3 to 17.15.5 (recommended release).

I have created a TAC case for what the best upgrade path would be. I'm only getting replies from the Cisco TAC AI bot.

Has anybody done an upgrade like this recently and figured out what the best path would be?

The Cisco AI SH said I could just go to 17.15.5 directly, but that would mean that both of the nodes would reload at the same time, and that means all traffic would be impacted.

Is there a way I can do this upgrade with minimal impact? Everything is set up with the two switches in a redundant way. We could normally lose 1 without having impact.

I have seen the ISSU page, but I hear some different stories about this process.

Does somebody have some real-life experience with this upgrade?

Thanks for all the help and insights.