Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.

Questions tagged [troubleshooting]

For questions requiring troubleshooting assistance with persistent/unresolved problems.

Filter by
Sorted by
Tagged with
2
votes
3answers
2k views

MTR packet Loss at intermediate hop

We are currently having issues with our WebService being intermittently inaccessible to clients. During diagnosis with the NOC and with some internal testing we believe we have a router dropping ...
2
votes
2answers
239 views

Cisco CoreSwitch 6509 Vlan connection problems

just wanted to ask what measures I'll have to do regarding on my problem on CoreSwitch 6509. I have 12 vlans on layer 3 switch which has 48 ports, 4 ports per vlan and I have a backbone on vlan 10 and ...
5
votes
2answers
71 views

Cisco 2821 hangs with “No memory”

I have one (pretty old) 2821 router, running BGP with 2 ISPs. (C2800NM-ADVENTERPRISEK9_IVS_LI-M), Version 12.4(24)T5 Sometimes for unknown reason it just hangs, and as it is remote location I cannot ...
24
votes
10answers
246k views

How to find the port a device is connected to, based on IP, on a Cisco Catalyst switch

On a Cisco Catalyst switch, I need to find what port an end device is connected to. I have the IP address/host name. How do I quickly find the port?
11
votes
4answers
34k views

Interpreting TTL in ping results

I work for a VoIP service provider and I am working an issue with a customer who has a cable internet connection that's throwing me for a loop. He has a single block, which we'll pretend is 70.141.15....
5
votes
4answers
6k views

DLink switch loses configuration on power off!

We just bought a DGS-1210-28P smart switch, it is my first experience with a business class switch, however I found a pretty weird behavior. The switch loses all of its configurations, even management ...
6
votes
1answer
425 views

Bandwidth limit Cisco 3400 ME problem

I want to limit bandwidth (speed) of interface of Cisco 3400 ME switch. I did these: policy-map parent class class-default shape average 64000 And in gi0/2 interface I apply it: service-policy ...
1
vote
0answers
301 views

Point to Point ICMP Ping Loss between Juniper MX routers

I am facing problem with regard to 1 x 10G link (which is actually configured as an aggregated Ethernet (ae) i.e ae link contains only single 10G link. This ae link is connected between 2 x Juniper ...
2
votes
1answer
39 views

How do I find out which NAT is getting hit?

I can see in packet captures that my packet's destination IP is getting translated. How do I find which NAT statement is responsible for the conversion if my device has over 200 NAT rules? I'm using ...
0
votes
0answers
118 views

Why can't I ping to the outside interface of my ASA

Below is the output of packet tracer. I have simulated a ping packet from 10.106.51.203 to 10.106.51.200. 'mgmt' is supposed to be the outside interface. Also, why is output-interface in the result ...
1
vote
1answer
308 views

Cisco 49XX multicast flooding

I have problem with multicast on cisco 4948. I've got vlan 9 with muilticast, which configured on several ports. Switch floods multicast traffic on all ports configured with vlan 9. It consumes link ...
3
votes
1answer
93 views

Cisco Router IOS update

I am facing problem in update the IOS of Cisco 7304 router. I am upgrading from 12.4(24)T2, to 15.2(4)S7 this. but I was boot from this version 15.2(4)S7 it booted proper from flash. But when I put ...
0
votes
1answer
94 views

How to Troubleshoot Network Latency Step by Step

Does anyone have an idea of how to troubleshoot high network latency step by step? For example, let's say we have a remote office. And all users are from that office are having high latency accessing ...
3
votes
1answer
359 views

Fix our Cisco switch overwhelmed by console logging

I have a setup with dual redundant Cisco catalyst 4506-E using the WS-X45-SUP8L-E supervisor engine and two 48-port switches below it. My task is to access and modify the switch configuration. ...
2
votes
1answer
676 views

Intermittent periods of high packet loss, one hop beyond router

I've been trying to diagnose internet connection issues at a remote small business for which I am the system administrator. If this is not the proper Stack Exchange to post to, I'd really appreciate ...
1
vote
3answers
27k views

Output drops/errors on Cisco 3850

Sorry if this is a noob-ish question, but I am a bit lost. We are currently having some network issues, that seem to be manifesting in what appear to me to be odd ways. End result is I have some ...
2
votes
1answer
2k views

continues to execute the command ping

tell me please why continues to execute the command ping... Router#ping vrf vrf-trust 50.50.50.50 sou 2.2.2.2 Type escape sequence to abort. ending 5, 100-byte ICMP Echos to 50.50.50.50, timeout is ...
1
vote
2answers
134 views

What can I infer about a network connection using a cable tester (if anything)

I have a NS-468 cable tester for testing cables. This works fine but if I connect just one end of a RJ45 cable to a network, I only get 4 lights. This seems reasonable as I suppose 4 pins are for ...
2
votes
1answer
61 views

Routing and Switching & network monitoring

hi i am facing problem in juniper switch Model: ex4200-48t ,Junos: 15.1R6.7 . i deploy network monitoring check-MK software. there is showing errors of juniper switch ports and also show in logs file ...
4
votes
1answer
157 views

PAT not translating at all

I am studying for my CCENT. I threw together a PAT practice lab. Other than DHCP and RIP everything is pretty stock. No VLANs No security Just NAT overload on ACCESS router. I am stumped why it isn'...
1
vote
0answers
22 views

Troubleshooting slow connections in large data centers [closed]

I’ve been asked this question - or a variation of it - during some recente job interviews. I think my answers were adequate (involving reducing scope, packet tracer with many probes, etc) but I’m ...
1
vote
0answers
37 views

Internet not working [closed]

I have this types of network in my office. Recently we have moved to new i BSNL internet. My problem is when i bypass router and connect poe cable to computer internet is working but when i put ...
1
vote
1answer
146 views

Cisco: Router can ping Internet, Clients cannot

I'm currently playing around with a Cisco 819 LTE-integrated (C819G-4G-G-K9) router at my summer place to get a better LTE-signal and control that the ISP router provides me. Currently I'm stuck at ...
3
votes
1answer
471 views

Problem with IP phones after ISP failover change

I've ran into a strange problem at one of my clients. They use ShoreTel Sky cloud IP telephony service and use Cisco 7960 IP phones hooked up to an ASA 5520. The configuration is done through IP SLA ...
13
votes
3answers
58k views

How to verify that a UDP port is open? [closed]

I have here a dilemma. I have a device that communicates to another remote device but there is a firewall between them. It's a UDP connection, so TCP utilities don't work to test if the specific port ...
4
votes
2answers
2k views

What is an acceptable spell of total packet loss for public Internet traffic?

The context: an Internet facing web site, streaming near real-time market prices. Paying customers can be anywhere on the Internet. The issue: Customers can experience total packet loss for 10s, 30s ...
8
votes
1answer
1k views

ASA5550 Error: assertion “_vf_mode_init” failed: file “vf_api.c”, line 99

I pulled an old ASA5550 off the shelf, which had 8.4(2) loaded on it. When I tried to boot it, I got the following error... ----------------------------------------------- Traceback output aborted. ...
4
votes
1answer
281 views

Latency in P2P Circuit

I have one P2P Circuit from our HQ to a secondary office. the distance between them is approx 2kms. Earlier when the Circuit was delivered at that time we were having an RTT of 3-4ms. It is a 10Mbps ...
0
votes
1answer
39 views

Mixed Use Four-pair Cable

My school tried to save money, so they decide to use an installed cable for phone, CCTV, and ethernet. I used two pairs for ethernet, one for phone, and one for a CCTV camera. The phone and camera ...
1
vote
2answers
78 views

Cat 5e wiring Type A incompatibility with Type B

I am not an engineer but I’m having problems with my small network in my business. I have 11 computers after 13 yrs am having major problems. My network keeps shutting down, and my dental software on ...
1
vote
1answer
294 views

Poor bandwidth after re-coupling an Ethernet cable

As part of an experiment I cut a Cat 5e Ethernet cable in half, stripped off a small amount of insulation on each wire and attached each pair of wires together with its own alligator clip. There are ...
1
vote
2answers
168 views

Cisco 1800 series: sys-2-chunkexpanfail: error every time

My knowledge of Cisco is very basic and I´m having this error constantly. I have to reboot every time, and it does not seem right. How can I solve it at once?? What I know of this device is that it ...
2
votes
1answer
496 views

arp or proxy-arp causing high cpu

We have an issue on a Cisco A901-6CZ-F-A with high cpu caused by Arp requests coming on Vlan11 from our customer. We enabled 'debug arp' to try and diagnose, below is a small snippet. IP addresses ...
0
votes
1answer
68 views

What are the “next steps” to take when business Internet service stops working? [closed]

Scenario (based on real events) a small business has a "BigCorp" Internet service. One day the Internet goes down after a power outage, and they call BigCorp for help. BigCorp support over the phone ...
6
votes
1answer
2k views

How do I create an SSL CSR via CLI for Cisco Prime?

I'm trying to create a csr for a cisco prime server. I managed to create a csr and put it in the "defaultRepo", which is local on the disk. After what I've read I need to create a certificate repo ...
2
votes
1answer
53 views

Different responses IP and domain name [closed]

I have a domain name that is using a public IP, when I send two requests, one to the domain name and one to the IP I get different headers in each one, in one of them 4 cookies are set, in the other ...
3
votes
1answer
4k views

Ping sometimes works and sometimes fails [closed]

I have a Cloud Core Router with v6.1 RouterOs. It has defined a PPPoE client, add-default-route to yes and masquerade to out interface. I can ping the router from any device connected to the internet ...
0
votes
1answer
455 views

Do I have to reboot the Fortigate 1000c after modification on static route?

I am using a Fortigate 1000c working on NAT mode. It has two WAN connections (WAN1 and WAN2). I am using a static route. For some reasons, There are many firewalls and routers (Cisco, TP-Link and so.....
14
votes
2answers
6k views

Troubleshooting low Metro Ethernet TCP throughput

The setup We have rented a few leased lines that present themselves as a layer 2 network, i.e. you have one big pipe at the datacenter and the remote sites have smaller pipes. Inside the layer 2 ...
4
votes
4answers
396 views

How do I fix my vlans connection to the Internet?

I have the following abridged configuration for a Ubiquiti switch: interfaces { ethernet eth1 { address 192.168.4.1/24 vif 101 { address 10.10.254.1/24 } ...
0
votes
1answer
684 views

Can't connect to FTP [closed]

I am using Beetel 777VR1 with Airtel Broadband. I am trying to connect with a FTP server but I am not able to access that. However with same credentials when I try to connect with my mobile ...
2
votes
2answers
470 views

ASA not passing traffic

I hate posting things like this, but we're backed into a corner here. We recently had a new client ask us to set up an ASA for their branch office 800 miles away. A colleague and I spent last night ...
1
vote
4answers
723 views

Sniffing a Device's Traffic on LAN

There is a device on my network connected via ethernet. Seeing as how hubs are hard to find or ridiculously expensive these days, what hardware can I use if I'm interested in sniffing the traffic to/...
1
vote
2answers
478 views

How to verify Voice QoS dscp and IP predecence traffic session?

How can I verify tht QoS is working for voice traffic? I also have voice server IP address. Can I also know what the session source/dest/port number info? class-map match-all avaya match access-group ...
3
votes
2answers
573 views

NetFlow-working one direction only

Cisco 3850/IP Base/IOS XE 3.7.2 I was going over my NetFlow data, and it seemed I was only catching flow in, and not out. I already had the in/out records and monitors, using the same exporter to one ...
2
votes
1answer
1k views

how to capture only SMTP using latest Wireshark 2.2.6 or later

I am debugging a problem with my Azure VM Windows server receiving SMTP from the Internet, and want to use Wireshark to show ONLY SMTP. I would also like to use Wireshark to show the contents of the ...
6
votes
1answer
913 views

7609 + SIP-400 PPPoE: cannot route to the Internet

I am trying to configure a 7609 router with a SUP7203BXL, SIP-400 and SPA5xGE as BRAS. The configuration is at the bottom of the question. The sessions are created, but the clients can't reach ...
3
votes
1answer
899 views

Adding encrypted password on Cisco 3560-CG switch

I'm trying to update the enable secret and account password on a Cisco3560-CG switch with an encrypted password shared by devices throughout the company. I use the following command for the enable ...
0
votes
1answer
542 views

Three SG220-50P switches are rebooting randomly every few hours or days

We have three small business PoE switches, SG220-50P purchased from two places. They are each randomly rebooting at different times every few days, and sometimes only after a few hours. They have been ...
1
vote
1answer
67 views

Consistent no route to host errors on servers

Servers configured with DHCP have a default route in the corporate network. Every time a "new" host is connected, a "no route to host error" is received. The second request after a few seconds works ...