Questions tagged [packet-loss]

For questions about packet loss, where one or more packets of data travelling across a computer network fail to reach their destination. This is typically used in troubleshooting, where either the physical medium or network medium has a defect.

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23
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2answers
2k views

Emulate Ethernet frame loss for testing purposes [closed]

Maybe I am missing something rather basic, but I don't know so I figured I would ask. In terms of testing, how sensitive various TDMoE are to BER and packet delay, I am looking into how to simulate ...
19
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1answer
3k views

Finding transparent firewall packet loss

We use the Cisco ASA 5585 in a layer2 transparent mode. The configuration is just two 10GE links between our business partner dmz and our inside network. A simple map looks like this. 10.4.2.9/30 ...
13
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1answer
114k views

What does TCP DUP ACK mean?

In Wireshark, I see TCP duplicate ACK packets sent from the receiver to the sender. What does it mean? Does it imply packet loss? Thank you
12
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3answers
24k views

What would cause really sporadic packet loss, when signal strength is fine

I have a router connected to a modem. My intention is to connect to this router from an office that's about 200 feet away and through 2 walls. The router signal is not strong enough to get to the ...
10
votes
1answer
2k views

measure one-way latency/jitter/packet-loss

I'm getting increased latency and StDev due to route congestion and packet loss, but the forward and reverse paths go over distinct networks (e.g. one being init7.net, the other one being he.net), so, ...
9
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4answers
2k views

Measuring per-link latency/jitter/packet-loss

I need to measure the latency, jitter and packet-loss per link in a network, as opposed to end-to-end, e.g. like this: s1-eth0 <--> s2-eth0 (~ 20µs avg. latency, standard derivation 10µs, 57 % ...
9
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3answers
6k views

packet drop on 10gb/s interface

I have a certain number of packets dropped on my 10gb/s interface, on Cisco 6500 with Sup 720. You can see underneath the number of dropped packet within a minute, after I cleared the counters. We ...
8
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1answer
1k views

Dropped data packet on satellite connection

We have several embedded pcs on farms in the UK and US. Among other connections these talk to our server sending a small packet of data (100 - 600 bytes) every 20 seconds. Over DSL this is fine. ...
8
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1answer
1k views

Unidirectional Packet Loss

Recently after upgrading several MetroE circuits (L2 connectivity) from 100Mbps to 1Gbps, I noticed that large file transfers fail between some sites; however, the transfer only fails in direction. ...
7
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6answers
3k views

Redundant IP link aggregation for failover operation without route failure detection

I am looking for a technology to achieve TCP connection fault tolerance with the help of two links between hosts and without time delays for route failure detection. Something like this: ...
6
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4answers
213 views

Packet Collison Avoidance

If a wireless network has collision avoidance, how comes the network slows down if more clients connect to it?
6
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2answers
3k 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 ...
6
votes
2answers
477 views

Why do wireless signals interfere with themselves regularly?

I come from a computer science background but physics is not presently one of my strengths. I've been reading some research regarding multi-hop routing of wireless (ad-hoc) networks such as this paper ...
6
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1answer
1k views

Cisco Nexus 3064PQ CPU spike causing packetloss

Nexus 3064 CPU spike and packetloss I have L3 Cisco 3064PQ switch which is running latest "nxos.7.0.3.I4.7.bin" basically I am using for routing so my ISP 2x10Gbps link terminated (with LACP) on ...
5
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1answer
19k views

TCP and Go-Back-N

While studying about TCP i notice that is very similar to Go-Back-N, but ,i think i'm missing something very important: In http://www.ccs-labs.org/teaching/rn/animations/gbn_sr/ we can see that in ...
5
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2answers
9k views

What is Packet Loss Rate?

I am confused on the definition of Packet Loss Rate. Is it the number of packets lost per unit of time? or Is is the number of packets lost per number of packets sent?
5
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1answer
1k views

Dropping packets routed between VLANs

I have a star topology consisting of 12 switches. Recently, we began running low on available IP addresses (192.168.100.0/24) and I was asked to open up a new scope (192.168.50.0/24) on the DHCP ...
5
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3answers
10k views

Some VPNs have 1-5% packet loss

I am currently in this situation and I'll try to be as specific as I can. My firewall has 20 VPNs (over the internet) with different vendors. Everything was fine til a month ago. I usually use ping ...
4
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2answers
2k views

Cisco ASA 5585X Internal-Data0/1 interface errors

I have noticed on Cisco ASA 5585 (SSP-20) interface error counter going up specially overrun but so far we haven't seen any production impact or issue, error rate is low so its not noticable but would ...
4
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2answers
3k views

Output drops on serial interface when service-policy applied

Our core router is a Cisco 7206VXR with NPE-G2 running 12.4(20)T1. It has numerous interfaces connected to WAN links (DS3, ATM DS3, 2xT1, onboard Gig0/1), and feeds into the LAN core with 2xGig ...
4
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2answers
898 views

High Jitter and Data Loss on Cisco Meraki Z1

Our office is running a Cisco Meraki Z1 Security Appliance and recently (March 5th) the internet has been dropping out intermittently. The appliance remains online but the internet either doesn't work ...
3
votes
1answer
2k views

overcome microbursts in cisco router or transmitting linux machine

I have linux machine multicasting UDP streams with Java applications. The multicats go though ciso router. I see lot of packet losses at receivers. Checking ports in routers reveals overruns counter ...
3
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1answer
651 views

What happens in SACK when there are multiple gaps in the received packets?

Suppose a client has received 0 to 500, 900 to 1100 and 1300 to 2000 how will ACK and SACK look like? Does it look like this ACK: 500 SACK:900-1100 and then it asks for the packets 1100 to 1300 in new ...
3
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3answers
7k views

RSTP and PVST mix in switch fabric

We have a Dell stack switch (running RSTP) connected with a couple of Cisco switches (running PVST), and recently, something happened. I'm not sure where, but in our network, we started getting packet ...
3
votes
1answer
8k views

tcpdump not capturing all TCP packets when capturing whole packets

I have a server and a client on different machines and on different locations. I'm trying to capture TCP packets with tcpdump on an interface of the server machine. I've injected an identifier in the ...
2
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2answers
73 views

Will packet loss get bigger if the hop count gets bigger?

This is a general question. Will a packet loss get bigger if there are more hops (and thus more milliseconds) along the path? Say, I ping a server1 from its default gateway R1 and get 2% packet loss....
2
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3answers
5k views

How to find packet loss in Wireshark network dump file?

I am a beginner in Wireshark, and I would like to find some problems with a TCP connection. Basically, I have some sockets timing out, and I would like to find out if the message (packet) being sent ...
2
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3answers
4k 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
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3answers
11k views

What causes packet loss when using full bandwidth from ISP?

We have a small, local ISP that is having some networking issues and I'm trying to understand the cause to better communicate with their network guys. I work with a number of companies with different ...
2
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2answers
1k views

How sliding window protocols handle duplicate packets caused by extreme network delays?

Let's say there is a network that sometimes delivers data with extreme delays. And there is a protocol that uses a "sliding window" algorithm for tracking packets acknowledgement. And imagine such a ...
2
votes
1answer
172 views

Bonding and switching between 2 different Links/WANs/Interfaces

Before I ask anything, I'd like to say that I pretty much searched a lot (to what I know of from keywords and terms such as "bonding" "wans" "links" "failover" "aggregate") and I couldn't find any up ...
2
votes
3answers
2k views

CRC errors and ICMP packets loss correlation

I would have a question regarding physical problem detection in a link with ping. The assumption is as follows: I have a fiber or cable with much of noise due to bad hardware (bad cable or bad ...
2
votes
1answer
2k views

How does a router behave when some of the fragments of a packet is lost?

Consider an example where host-A is sending data to host-B. While the fragments traverses many routers in between, some of the fragments are lost. So now the router identifies this and waits for that ...
2
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2answers
943 views

Cisco 2950 switch LED off timeout

Some random ports led turns off for less than a second https://www.youtube.com/watch?v=eUl4ifveh74 Right in that time i have 2 timeouts in one or more ports which turned off . why is it doing that? ...
2
votes
1answer
31 views

Should Bit Errors Cause Loss Proportional To PDU Size?

Should I expect random (or even regularly-occurring) bit errors to cause corrupted/dropped PDUs (packets) proportionate to the PDU size ? Troubleshooting high (0.01% to 0.1%) packet loss over a short (...
2
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2answers
66 views

What NIC card should do before transmission

When a computer X is about to send a set of frames over the network to computer Y, should the NIC card of the computer X notify the other computers' NIC cards on the same communication link before ...
2
votes
1answer
97 views

Outer routing switch - collisions and packet loss

Currently I have experienced collisions and packet loss on an outer routing switch (1-2% from the States and above 6% when tested from Europe). In a basic way infrastructure looks like Where outer ...
2
votes
1answer
1k 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 ...
2
votes
2answers
932 views

1522-byte frames from access point being dropped by gateway

EDIT 2: This may be a bug in the kernel or module. Reported here https://bugzilla.kernel.org/show_bug.cgi?id=109471 Can anybody confirm that this phenomenon is definitely out of spec? Original: I'm ...
1
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2answers
4k views

What could cause network to duplicate packets? STP during convergence?

I have understood that real networks have routing changes, leading to out-of-order delivered IP packets. Real networks also have frequent packet loss. However, what I have not understood is why could ...
1
vote
2answers
171 views

How ethernet links can have a delay and loss

In some simulation environment, such as mininet, you are given parameters when you define your virtual link between switches such as: bandwidth, delay, and loss. I understand a link has a bandwidth ...
1
vote
1answer
198 views

What happens when an intermediate hop router encounters a packet whose MTU size is more than what it can handle?

Basically if the frame size of a packet is more than the MTU size configured in the router (which is an intermediate hop) the packet is dropped. Since IP does not have any ARQ mechanism, is there a ...
1
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2answers
362 views

can the loss of 4 packets in 1000 cause performance issues

A network engineer spotted some packet loss averaging 4 packets in 1000 then some body tried to use that as a cause for a performance issue. Is this a realistic assumption that that sought of loss can ...
1
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1answer
2k views

MTU 1500 gigabit connections translated to 9000 jumbo packets over 10 gigabit connection

I'm testing the frame size by adjusting it from 1500 to 9000 for the link to the storage NAS to optimize the 10 gigabit connection and have seen an increase of speed to almost 300% read speeds. I ...
1
vote
1answer
486 views

TCP and internal packet retransmission

When point A sends data to point B, it's delivered reliably over TCP. If the underlying channel loses data, the TCP stack on point B side automatically asks to re-transmit lost frames. Let's assume ...
1
vote
1answer
128 views

Should using full bandwidth cause packet loss and latency (domestic cable service)?

I'm noticing large spikes of packet loss when using maximum of my 30/1 HFC cable connection. Is that normal, or should I talk to my ISP? E.g. when downloading something at close to 30mbps or ...
1
vote
1answer
61 views

How to score links in a network represented as graph?

I am working on an academic research about networks. I have proposed my model a a graph that nodes are users with commodity hardware connected to each other via internet as graph links. I know this is ...
1
vote
1answer
211 views

Routers and output buffers: Why can two devices interfere with each other and cause latency?

I apologize if this question has been asked already because I couldn't find anything related. I'm a beginner in networking and am reading through Computer Networking: A Top-Down Approach, as well as ...
1
vote
2answers
55 views

Network Packet that allows maximum throughput

I created a basic wireless system between two microcontrollers. Each uses the on-chip UART and an HM-TRP radio module to communicate with each other. Eventually I'll have a master-slave setup where ...
1
vote
1answer
426 views

With large file transfer packets are dropped with the error "IDP detection OOO Exceeded Max" on encryption/decryption engine subsystem

We have an in-house application for sending large files. Using TCP/IP this application uploads the files to a server on our main office network and then sends a link to the file as part of an email. ...