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Questions tagged [packet]

99 questions
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Extremely flaky connection to our EC2 instance through one connection, but not others

We have a robotic coffee barista deployed at the Dell campus in North Austin, with internet service through Time Warner Cable. We have been fighting intermittent connection losses between 10PM - 1AM for 3 of the past 5 nights. Time Warner has been…
Rjak
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Getting chunks of high ms when pinging local / external IP addresses?

I am having difficulty identifying what a specific problem with one of your vlaned networks. They have a voip phone which regularly cuts out during long phone calls. I have done several ping tests from both the phone and directly into the ethernet…
Baz
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How to redirect a packet with iptables that match a certain pattern? (eg a QUERY command with UDP)

I have a certain packet that I want at all times to be redirected to a specific ip on my virtual network interface. As for now my iptables is setup like this: (the commands, I use \ as for now to make it more readable, read as "combine next line to…
Gizmo
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How many times does switch calculates FCS?

Does a switch calculate the Frame check sequence (FCS) before sending packets? Because packet shouldn't change, so FCS should also stay the same.
RebelUA
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See historical packet receipt statistics in Windows

I know this is a long shot, but it would be really useful to me right now. Does anyone know of a Windows function or 3rd party tool that can show stats about the receipt of packets on a network adapter historically (over the course of the few days,…
Raiden616
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tcpdump show strange packet with incorrect src ip and dst ip

I have private LAN with > 100 servers, in which, I have 3 server: x.x.x.37: run memcache on port 11211 (called s37 for short) x.x.x.241: run an application server, which connect to memcache on x.x.x.37:11211 (called s241) x.x.x.46: test server.…
Eddie Bui
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How many packets will it take to send particular data?

If I know the maximum packet size is 1500 bytes say for Ethernet frame v2 then for example I want to transfer 1 KB over the Internet which is roughly 1024 bytes. Will the packet be split into many packets upon sending it or will it be just one…
cpx
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forwarding of small and large packets: any difference?

When it comes to simple forwarding of packets (no errors being generated), are packets processed faster by routers when they are small as opposed to when they contain a large payload? Or do routers work exclusively on a per-packet basis, so…
Ricky Robinson
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Dropping Packets Randomly

I have a SuperMicro Server based on the X9DR3-LN4F+ motherboard from SuperMicro. Original intentions for the system were quite different from what it has ended up serving, but that happens. It is being used for a IP Video Security…
JTWOOD
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What does a packet capture in pfsense do?

I have some issues with a third party to establish a VPN connection. To debug it, I made a packet capture on the device that represents our synchronous DSL line. The solution I'm using is an old pfsense-1.2.3 and I've initiated the capture using the…
noamik
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Getting packet rate with tcpdump or iptables

I need to get the rate at which certain packets (i.e. LDAP) arrive on a interface in a linux environment. I was thinking of using tcpdump to filter the wanted packets and subsequently monitor the rate at which rx packets are seen. Perhaps by…
vobelic
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Caculating packet offset

In Wireshark, if I want to write a filter which accepts only ICMP destination unreachable ( type 3 ) messages, the filter is icmp[0] == 3 . How do I count the packet offset of 0 in this instance ? EDIT Based on the above image from Wikipedia, the…
iridescent
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SMTP port open - but not open

As some of you might know, I am setting up an exchange server. Now I ran into another problem: I cannot connect to the SMTP service from outside the server! The ports are opened in the gateway device (a ZyXEL USG50), Windows firewall is off. I see…
Frederik
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How to block specific UDP packet outgoing from machine using iptables

I want to block specific UDP packet OUTGOING from my machine using iptables. Packet has a string in "hex in RAW"(?) i want to check packet by it. Like: If UDP packet hex RAW match "test_text" - block it. //EDIT: i have something like this iptables…
wlodzimierz
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TCP firewall allows connection to external server but blocks response packets?

Consider this basic network setup: Client -> Router -> "Internet" -> Router -> Server Problem: the client can open a connection to the server and send data ("request"), but the server data packets ("response") can not be sent to the client. It looks…
mjn
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