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Questions tagged [errors]

For questions about interface errors on a network device. For instance, you have an interface with a lot of input errors, but you don't know how to troubleshoot it.

3
votes
1answer
49 views

Resource Errors on 1G interfaces in Juniper router

We are observing resource errors on almost many 1G links on Juniper MX240. The resource errors counter is quite high. The MPC type is MPC Type 1 3D. I am sharing the output of command 'show interface ...
1
vote
1answer
53 views

Intermittent issues on a dark fibre point to point link

After a bit of advice on an intermittent issue i'm investigating. We have two buildings on the same site connected by 548m fibre run that we own and it was installed around 10 years ago. Over the ...
2
votes
1answer
75 views

Layer 2 error correction

How are acknowledgement sent at data link layer to the sender when crc of frame is incorrect?
1
vote
1answer
155 views

User Datagram Protocol (UDP) protocol can error control?

UDP can congestion control? UDP can flow control? UDP have some error correction mechanism?
0
votes
1answer
270 views

Layer 2 ARQ protocols

Some authors (i.e. Tanenbaum, Stallings) reference ARQ protocols as layer 2 mechanisms for handling errors. Even this page from Wikipedia says that these protocols reside in the Data Link or ...
2
votes
1answer
47 views

How often does it happen that at the Layer 2 (MAC) an error goes undetected?

I know there are certain error detecting and correcting codes added at the Layer 2. However is it still possible to have errors go undetected eve with the addition of these codes? What type of ...
5
votes
1answer
794 views

Physical layer errors in Ethernet

What happens if an error is detected at the lowest possible layer of the stack ISO/OSI for Ethernet? For example, considering 100BASE-TX, it is implemented with a 4B5B coding this means that there ...
2
votes
2answers
2k views

cisco Total output drops on interface

we have c3850 trunk with other switch 4948 and its LACP 4x1G interface bonding (etherchannel) out of 4 1G we are getting Total output drops on 2 interface. This is all started yesterday when i ...
2
votes
4answers
533 views

Why are there error detection methods in almost every layer of a network?

What is the purpose of checking errors in almost every layer of a network? For example, I don't see the purpose of using a checksum in TCP given that CRC has already been checked in lower layers. Or ...
0
votes
1answer
2k views

Underruns in ASA interface

I have an ASA firewall in production. When I issue the show interface command, there are lots of underruns and it keeps increasing. I have change the LAN cable, reset the interface, enable and disable ...
5
votes
1answer
658 views

In Cyclic Redundancy Check, how does the receiver knows what the generator polynomial is?

Must the receiver know the generator polynomial in order to detect the errors in the received data? So how does it know what generator polynomial the sender has used?
1
vote
1answer
316 views

How can I test my ping application for proper detection of ICMP return types and codes [closed]

I have developed an application that partially replicates the functionality of the builtin ping application, essentially sending an ICMP packet, receiving the response, and parsing the header. ...
3
votes
3answers
1k views

What is “collision domain”

In Tanenbaum's Computer Networks: What happens if more than one of the stations or ports wants to send a frame at the same time? Again, switches differ from hubs. In a hub, all stations are in ...
1
vote
3answers
326 views

All tunnels down on Cisco 7204VXR with debug message “Unable to generate DH phase 2 parameters!”

I have 40 or 50 tunnels with over 200 SAs active on a 7204VXR with NPE-G1 using the software crypto engine (no VAS card installed). The working config was transferred over from a 2821 with AIM-VPN ...
5
votes
2answers
2k views

ASA VPN communication issue

I have got an issue where SPOKE 1 and SPOKE 2 cannot communicate with each other. However, SPOKE 1 and SPOKE 2 can communicate with HUB. Please see configuration below for spoke and hub. SPOKE 1 (...
4
votes
2answers
676 views

Multiple error types Cisco 861 router

I have a connection that users complain is really slow at times. My SNMP graphs from Observium don't show the bandwidth being fully used or high latency. They show a lot of errors on the WAN port of ...
6
votes
1answer
570 views

Juniper MX-5 EOPE Drop Pkt Cnt Incrementing

When running show pfe statistics error on a a couple of MX platforms, I see the EOPE Drop Pkt Cnt counter incrementing on 6 MX's out of 22. I believe these are "End-Of-Packet errors", but can't find ...
2
votes
1answer
933 views

Why am I having issues accessing a website hosted on servers behind a load-balancer?

I am having an issue with an offsite location accessing a website that is hosted on 3 servers behind a Coyotoepoint Load-Balancer, at our Corporate Office. We currently have well over 500 locations ...
10
votes
2answers
2k views

Cisco 7604 + RSP720 3CXL + WS-X6704-10GE increasing the error counters on the port, but there is no loss through the port

Cisco 7604 + RSP720 3CXL + WS-X6704-10GE increasing the error counters on the port, but there is no loss through the port: #sh interfaces Te3/4 TenGigabitEthernet3/4 is up, line protocol is up (...
4
votes
1answer
2k views

CRC & Align Errors on D-Link switch, network down

I have network topology: (room 3) D-Link DES-1024D | | (room 2 MAIN) (room 4) Baseline 3COM Switch 2948-...
6
votes
2answers
2k views

Cisco 7609-S Line card error counter is regularly exceeding threshold

I am receiving the following syslog messages on a 7609-S. Jun 17 11:52:27.560 BST: %CONST_DIAG-SP-4-ERROR_COUNTER_DATA: ID:47 IN:4 PO:255 RE:169 RM:255 DV:5 EG:2 CF:10 TF:472 Jun 17 11:52:27.560 BST: ...
4
votes
4answers
2k views

Cisco 2600 series router logging a lot of “Memory allocation failed” errors

We are getting the below two error messages randomly on a 2600 series router. Syslog shows the router has been fine up until a few days ago. Would a reboot most likely cure the issue or is it most ...