Questions tagged [packetloss]
Packet loss occurs when one or more packets of data travelling across a computer network fail to reach their destination.
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Packet loss with local WebRTC clients
I stream live audio to clients via WebRTC, and a streaming app called Barix on a local network for translated events.
When there are more than 20 or so clients, the network undergoes significant ...
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The TCP receiver only ack the minimum bytes of MSS one by one
The client and server nodes are CentOS7.9/X86_64. If the HTTP POST requests were sent directly to the server, there are about 0.2% of cases that may timeout. If the HTTP POST requests were sent ...
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Causes of packet loss on multiple persistent tcp connections simultaneously?
The issue was detected while analyzing some application logs, which reported few seconds long spike periods when messages from multiple clients are received on the server with a substantial delay (up ...
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DHCP Discover Packets don't reach server
I have a dumb IoT device that simply asks for a DHCP lease and gets no answer. I figured out that the request never reaches my routers DHCP server and I have no clue on why that happens. If I run a ...
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High Packet Loss on Device when Plugged into Unifi Network
We have 3 large format projectors of the same model on our network all plugged into a small switch. Recently, we have been unable to reliably load 2 of the 3 projectors' web management pages. Further ...
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MULTI: bad source address from client [x.x.x.x], packet dropped
I had a running OpenVPN server on a RPi (buster, Debian 10). After upgrade it stopped working completely. Before that I had some issues with some public networks, which I did not investigate.
When I ...
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DNS lookup failing even though tcpdump shows that nameserver has responded
DNS lookup on some of my EC2 instances have been failing intermittently. A reboot resolves the problem but it goes back to the same fail-state after a few hours (or after a few days), and remains in ...
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Ubuntu 20.04 LTS MTR _gateway reporting nearly 100% packetloss, clients experience stutters and lag
I've recently come into some hassle with my dedicated server. I've done as much debugging as I can myself, from running tracerts and pings with a script. Watching the throughput of the server, its ...
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How to simulate what happens inside the packet buffer of a simple switch?
I'm debugging a case of UDP packets lost in a store-and-forward gigabit switch and I wanted to visualize what happens inside the switch to better understand the gist of the problem.
The scenario is ...
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Can many connections cause dns lookup or request timeout?
I'm running crawler on my company's internet. 10 raspberry pi * 45 crawlers each, 2 desktops * 70 crawlers each
These processes are sending requests 24/7.
3~5% of packets are getting lost. This is ...
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ksoftirqd maxing out for network interfaces
We have a Debian server with one link to the internal VLAN, and one to the external - both connect directly to the same switch.
On both links, we're intermittently seeing an unusually high amount of ...
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Spanning tree causing packet loss between a Cisco switch C3560 and Linux server running on CentOs
I am working in a network environnement where I have some Cisco Switch WS-C3560X-48 and Linux Servers running CentOS 7.7.
The linux servers are connected 3 times on my switches : one admin link, one ...
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iperf3 showing packetloss between 2 directly connected servers
I have 2 Dell PowerEdge-R620 servers with following configuration
Processor: 2 X Intel(R) Xeon(R) CPU E5-2637 v2 @ 3.50GHz
RAM: 64GB
Storage: 10 SAS drives (10K RPM) with RAID 10.
NIC: QUAD Ports 2 X ...
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Reliable transfer protocol designed for a known static bottleneck size and high packet loss?
AFAIK, most reliable transfer protocols like TCP tends to use some method (like packet loss) to detect the size of the bottleneck.
In my use case, however, the bottleneck bandwidth is a known value of ...
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Why am I not receiving a response when the request is sent through a load balancer and the response is too big to fit into a single packet?
There's a certain condition where I'm unable to receive a response from an HTTP request to a particular service: the request is sent through a load balancer and the response is too big to fit into a ...
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Troubleshooting TCP (but not ICMP) packet loss
I have server A and server B, with A attempting to open TCP connections to server B. curl shows that approximately 5-10% of connection attempts time out.
mtr shows 0% loss to B, and at intermediate ...
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Packet Loss between server-to-server Oracle Linux 7.9 bond
I have 2 Oracle Linux 7.9 physical servers, each one with a dual nic. I bonded this dual nic end attached server-to-server with 2 cables (not crossover cables). I have packet loss in average 50% ...
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Where can I get outage updates/alerts for transoceanic cables (and other tier-1 fiber backbones)?
Is there some site that aggregates status updates from the companies that manage the transoceanic fiber cables so that I can get a world view of global internet outages that break connectivity between ...
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Packet loss with TP-Link switch and Linux
I’ve set up four Linux servers. They’ve all been imaged the exact same. I got a cheap TP Link switch which I plugged them all into. When all turned on and plugged into the switch the machines seem to ...
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Need help troubleshooting periodic wireguard packet loss
I have a VPN server with Wireguard and OpenVPN on it. Most of my tunnels are OpenVPN, but I am working on transitioning over to Wireguard. The Wireguard server is at a main location, and I have 3 ...
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Debugging network issue
I've had this issue ever since I got this new router and flashed it with dd-wrt.
It's not really impactful (I'll describe the scenario) but I'm curious about it...
This is the diagram of the network ...
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Linux server dropping RX packets in __netif_receive_skb_core
I have an Ubuntu 18.04 server dropping received packets and I cannot figure out why.
Here's a graph of dropped packets from netdata:
The server is running multiple docker containers and networks, ...
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Measure packet latency / drop between ingress and egress interface of a rate-limiting pass-through host
Somewhere between my sender and receiver, there is host explicitly limiting my transfer rate.
I know it's a Linux host. The ingress interface for my traffic is eth0 and the egress interface is eth1. ...
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Why the packet loss of ping and traceroute is different
I have an IP address on 12th hop. When I send an icmp request packet with TTL 11 to this IP, the packet loss at the 11th hop is 0%.
However, if I ping the IP address of the 11th hop, or use TTL 11 to ...
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How to find root cause of throughput decrease and packet loss increase?
Short summary of my issue: How or why can a stable server suddenly start to perform worse for several days, only to later (seemingly automatically) return to normal?
I'm doing some performance ...
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Changing Linux kernel network settings on active live TCP sockets
If I change settings like this for example:
# sysctl -w net.core.rmem_default=500000
# sysctl -w net.ipv4.tcp_rmem='4000 90000 10000000'
Is it safe to do this in a heavy duty live production ...
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Ping packet loss even though the target is reachable. Does this mean packets are eventually getting through?
If I do ping 8.8.8.8 sometimes it returns the following for a period of time:
From 172.22.1.1 icmp_seq=36 Destination Host Unreachable
But at other times it does reach the target and yet it says ...
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Analyze Packet Loss Bursts
I need to analyze packet loss bursts in TCP streams. Given a number X a packet lost burst is when more then X consecutive packets got lost. So I have a pcap file and need to count how many bursts ...
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How to detect packet loss between two Win 10 computers?
I have an issue where an app that is dependent on file locks crashes on Windows 10. The programmers tell me that app is extremely sensitive to packet loss, so I would like to detect what is happening ...
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Packets drop in a Linux node
I've run dropwatch and this is the result I got:
dropwatch> start
Enabling monitoring...
Kernel monitoring activated.
Issue Ctrl-C to stop monitoring
39 drops at tcp_rcv_state_process+1b6 (...
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constant packet loss in internal ESXI network
I am new to Vmware Esxi and im doing testing for an experiment with an Vmware ESXI 6.0.0 server. on the server there is two Ubuntu guest clients with one VMXNET3 each, both on the same Vswitch.
Upon ...
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Linux TCP/IP tuning for low throughput network?
I have two linux machines connected by a radio modem. The bandwidth is about 2kbps, with ping times of around 400ms (5% packet loss).
Currently, ssh sessions have a delay in the order of 5 seconds, ...
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Periods of high packet loss, two ethernet cables plugged into TWC modem
A small business for which I am the system administrator has been experiencing intermittent internet dropouts. There seems to be no pattern to the dropouts — sometimes there is nothing for a week, and ...
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Linux bridged network intermittent packet loss (KVM context)
I have a standard bridging setup between the real world and a KVM VM guest.
Bridging looks fine:
[root@t ~]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.40f2e9c6033d ...
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multiple macvlan devices and policy based routing confusion
I have a server (ubuntu/debian) with two ISP connections. Both of these WAN connections have multiple public IP addresses.
(big pipe)----eth0-->\
> server ---eth2--(...
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Fine tune a Remote Desktop Gateway server to tolerate packet losses
I have a Windows 2012R2 server acting as remote desktop gateway for a number of RDSH servers inside the perimeter, and have a firewall between it and the Internet allowing access from outside to that ...
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Effects of packet loss on video streaming
We are sending an MPEG2-TS/H264 video stream over the network. This video stream is received correctly over the LAN, instead on the other end of a private WAN video quality is poor, thus suggesting ...
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Unstable ethernet/fiber pc to pc connection Windows
We have two Windows 7 PCs (64 bit) connected to each other directly, i.e. without a router in between, using a fiber connection with two ethernet-to-fiber converters. PC1 uses a Realtek PCIe GBE ...
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Detect faulty physical links with ping
I have a question regarding detecting a physical link problem with ping.
If we have a fiber or cable which has a problem and generate some CRC errors on the frame (visible with switch or router ...
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How can I identify the cause of packet loss in DNS?
We have upgraded some of our routers to Ubuntu 16.04 and are now getting some performance problems with DNS. It seems that packets are sometimes truncated, but I have no clue what else I can do:
This ...
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Optimize TCP connections between two Linux hosts connected by a long lossy channel
I have two distant hosts. Packet loss is always 19% until the rate exceeds 210 kB/s. The RTT is about 220 ms. The TCP congestion control algorithm is "cubic". "f_rto" is enabled. The actual speed of a ...
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High TCP reset and packet drop count on CentOS Linux
I have a small farm of web servers (HP Proliant and IBM x, with Broadcom Corporation NetXtreme II BCM5 NIC's) running Apache 2.2.15 on CentOS 6, behind a Cisco ACE load balancer, serving a PHP/JS ...
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What is an expected TCP retransmission rate
I have a direct connection setup between my NAS and server with two gigabit links bonded in mode 0. I also have a single gigabit link from my server to my network. I want to test how the bond is ...
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Can't ping between two VMs
I have two VMs that, up until yesterday, have been able to talk to each other just fine. Now they don't. I've been trying to get this fixed for several hours now, but haven't been able to figure ...
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Is it normal to have HTTP 499 errors in 1 out of 4000 requests?
I made a website, behind CloudFlare, and sometimes I get an early terminated (nginx 499) request, which is really hard to work around in the codebase.
This happens in about 1 out of 4000 requests.
...
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Troubleshooting packetloss
I currently own a couple of CS:GO gameservers which are hosted in Germany (hetzner). Recently (for the past weeks) some people have been getting weird lags (getting slightly teleported back, some of ...
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VMWare vSphere packet loss
I have a Dell Blade Enclosure with 14 blades and ESXi 5.5 on it. On blade 7 and 14 I have round about 65 % packet loss when I ping the ESXi Management interface. On all other blades there ist no ...
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Packetloss over Internet for "Linux-Linux" but not for "Windows-Linux" (tl;dr: it's MTU)
I am right now getting additional grey hair fighting a phenomenon concerning packet loss between machines on the Internet.
Check the diagram below. Note that whenever I use "SSH" I could use "HTTPS"; ...
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OSX how to drop packets randomly
I am testing the resilience of one of our streaming applications to handle packet losses. On linux machines I normally use iptables to randomly drop packets like this:
iptables -A INPUT -m statistic -...
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ICMP Packet Flood a local device over Wireless AP to figure out packet loss?
I'm using a utility to create an ICMP packet flood/attack called Hyanea since windows doesn't have native support like linux does.
I want to be able to test a new AP to see if any packet loss occurs....
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