Questions tagged [performance]

For questions about network performance, where factors like Bandwidth, Throughput, Latency, Jitter and Error rate are all often considered important.

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2
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1answer
109 views

How do CPU and RAM affect a router's performance?

I've seen a lot of circumstances when there are 50-100 users in the net cafes -- under normal gaming and web browsing activities with no heavy downloads -- causes the router to drop packets (leads to ...
0
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1answer
35 views

Realistic Benchmarks for Comparing VPN Performance

I'm looking to quantify the performance of different VPN technologies as part of my PhD thesis and want to know if there are any standard metrics for end-to-end performance that are used to compare ...
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0answers
26 views

ttcp command missing on Cisco 3850

We operate a hub-and-spoke network. The hub is a 3925. I have been using the ttcp command between the hub and each spoke to measure bandwidth. I realize that the test is flawed, but finding relative ...
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3answers
56 views

High Throughput on BGP Multihomed Network

I've One site connected to my server location via BGP over MPLS and at my server location 2 edge routers cater these WAN links, and are further connected to Servers via switches. Now, Is it possible ...
0
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3answers
65 views

How can we troubleshoot Wifi problems apart from the basic tips?

We have a Zyxel Wifi with an NXC2500 and two WAC6503D-S access points in our office. Around 30 devices are connected. We have both a 2,4GHz and a 5GHz radio active, both on channels without known ...
0
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1answer
109 views

Measurable performance impact of port mirroring on a firewall\security device?

I am setting up a network monitoring device which recommends that I create a mirror interface on my firewall/security appliance and send all packets to the monitor for sniffing, logging, and ...
0
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1answer
105 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 ...
2
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1answer
35 views

Random intercontinental TCP streams are slow

I have a home server in New Zealand and a remote server in Amsterdam of the following configuration: I have a simple test script: #!/bin/bash for i in `seq 1 20`; do scp root@remoteserver:~/...
9
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3answers
2k views

Is there a performance difference between a managed an unmanaged network switch?

Is there a tangible difference in speed/latency between a managed and unmanaged network switch?
2
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1answer
96 views

Definition of bandwidth capacity for an internet connection

First, I want to test the data rate of a fibre-optic internet connection, but I understand that results are affected by the circumstances of the test, like number of hops between the CPE and the other ...
2
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1answer
846 views

Is this a normal TCP retransmission pattern?

Our organisation's desktop computers have been performing not satisfactorily during their accessing of network resources. Out of suspicion, I perform a TCP retransmission statistics. Below picture is ...
1
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1answer
73 views

Can bad cabling affect the overall network?

TLDR: Can a handful of problematic lines negatively impact the performance of the network as a whole? ... or would any problems stop once it reaches the switch? Longer Version (background): A ...
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1answer
2k views

TCP DUP ACKs occurring on a seemingly regular basis

I noticed this while checking the performance of our Teamviewer connections. If i start a download test, the following pattern can be observed in the TCP stream graph provided by Wireshark: The red ...
1
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1answer
896 views

How can I calculate the network throughput using ping responses?

I have the tcpdump data for the below mentioned command.This is to perform a test on the network to derive the bits per second. Is it possible? sudo ping6 fd9c:b4f9:3108:1045:213:5003:59:324e -c 10 -...
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2answers
414 views

how to find the right value of MTU Jumbo frame

we take the decision to set jumbo frame on all our linux machines we have hadoop cluster with master machines , workers machines and kafka machines our switches ( Cisco ) are suitable to Jumbo frame ...
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0answers
107 views

PPPoE Performance Test

I'm looking for some tool or a way to execute performance test with pppoe account. simulate PPPoE sessions and traffic. Example: I have a PowerEdge R420 running a VYOS, I was wondering, how is the ...
5
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2answers
2k views

Cisco ISR 4000 Performance Levels, router shaper

I am trying to understand Cisco ISR 4000 Performance Levels. In the document ISR 4000, one can read the following paragraph: It's actually quite simple. The router shaper applies only to traffic ...
2
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1answer
85 views

ACL on Nexus 3064PQ performance

We are using this switch as L3 and planning to run some ACL to stop bad traffic. I never run ACL on switches so wondering is there any performance impact or how bad it will be? if anyone has any ...
1
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2answers
787 views

Cisco performance issues C890 series

I'm working on a complex project that includes Linux and Cisco routers. I am fairly new to networking and i'm using cisco command lines for the first time, so please be nice and don't hesitate to ...
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3answers
1k views

Why such a large discrepancy between theoretical and real Wifi speeds?

I am testing the actual speed of transferring a file from a network share. Over my 1 Gigabit Ethernet I get about 120 MB/s - that's 96% of the theoretical maximum. Over my old Wireless G I get about ...
2
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2answers
88 views

How to design a wireless network for efficient multicast or broadcast communications?

First, a little bit of background information: I'm working on some custom software that allows a group of computers on the same LAN to co-operate on a real-time task in a distributed, fault-tolerant ...
2
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8answers
270 views

What are the concerns other than latency for network tuning?

Everywhere I keep finding "to achieve low latency" or "latency is of concern", do this! So, I don't really get what are the other concerns other than latency. I mean who doesn't want low latency? Or ...
1
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1answer
36 views

How to make a web application run as fast as when I run it directly through the server? [closed]

I have a web application that run from a local server. When I run the application from the server using remote desktop connection, the application performance is smooth and fast. For example, ...
3
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3answers
168 views

Cisco Aironet performance took a big hit with VLAN

I manage a wireless network of 50 Aironet 1130AG access points spread across 8 Catalyst switches. This ran very smoothly until I had to employ VLAN tagging. There is now the passwordless Default (1) ...
1
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1answer
152 views

Cisco ACL performance question?

We have ASR1006 Router and we are running ACL on it to allow specific port to specific server. Question is there any ACL performance impact on individual IP vs full subnet. like following example. ...
4
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1answer
699 views

IPv4 vs IPv6 performance

What are the differences in performance for IPv4 and IPv6? Is there much of a difference in speed? and what are some of the methods that could be used to test this?
2
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1answer
31 views

What is the N½ value of a network?

In the context of HPC interconnect networks (Infiniband, OmniPath, ...), I've come across the notion of the N½ value of the network, which is supposedly some performance number. What is this number? ...
1
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1answer
3k views

General best practice for VLANs and domains

I recently took a job at a school. This is only my second position as an IT professional. My only experience with corporate networks is in a large school district at another school. They used VLANs to ...
0
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1answer
3k views

GNS3: performance tests using iperf3? [duplicate]

I'm running some performance tests on GNS3 (I know I shouldn't, but it is not until Friday that I will have the college lab available), and I'm trying to compare real BW or "speed" and theoritecal. ...
1
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1answer
109 views

NIC speed and PCI bus speed to be synchronized?

Is there any advantage point of having a Gigabit Ethernet if the PCI bus connecting NIC to Memory is a lot slower than that say just 80 MBps? In other words, I am trying to conclude that it makes ...
2
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2answers
81 views

Effects of local switch time on network performance

Given a collection of switches all communicating together, will the local time on the switching equipment configuration have any bearing on performance, or just a common reference point when ...
4
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2answers
229 views

Measuring route processing time

I want to feed a Juniper router a set of routes via BGP and measure how long it takes the router to process them, including time spent on prefix filters and RPKI origin validation. Cisco IOS XR ...
0
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1answer
68 views

Simple way to monitor network performance w/o access to network infrastructure?

I work for a large organization where the network team is in some disarray (key people left/fired, etc.). My team is responsible for the performance of various client/server applications which of ...
2
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2answers
1k views

Difference in latency between public and internal IP addresses

Should there be a difference in latency when accessing resources by their public IP address versus their private, internal IP address? And if there is, would (mis)configuration be to blame? My ...
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0answers
93 views

CDN performance degrading during load testing [closed]

While load testing our website through Soasta we found that the API calls were performing consistently without any degrade in performance (thanks to larger Ec2's serving them and the Elastic Load ...
3
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1answer
857 views

How well does 802.11k actually perform on large-scale networks?

As a student employee I've done some research on 802.11k and I understand that it's intended to help with devices roaming and also helping the client decide on the best (B)SSID to join. In practice ...
3
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1answer
930 views

Performance differences of logging session-init and session-close invididually compared to through apply-groups

Assumption: Your interest lies in logging each and every session Approach 1 You configure the session logging within each and every policy, for example: set security policies from-zone trust to-...
6
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2answers
14k views

How to “size” a Router for a Given Uplink

I'm the tech guy for a small business. (15 office computers, ~15 staff BOYD's, ~30 guest devices.) I'm looking to replace our Asus RT-N53 with a business class router and two access points each ...
3
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1answer
689 views

Firewall Benchmark- Concurrent connection metrics

I intend to perform a Firewall Benchmark. I have reviewed related research papers and RFCs to create a suitable methodology. I have also examined open-source tools useful for the project (iperf, ...
5
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1answer
988 views

ACL on entry of Core Switch - Performance doubt

We are an ISP and I would like to implement ACL to protect our core network (Infrastructure) and implement some filtering on public subnet inside. As border device we have a cisco WS-C4500X-32 4500x ...
3
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1answer
4k views

standard results for gigabit ethernet iperf

I can't achieve good transfer rate through scp and I wonder if the network configuration isn't tuned up correctly. I've noticed some differences when running iperf through tcp vs udp. Are these ...
9
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2answers
466 views

How to handle performance degradation deep in your provider's network?

What are some possible ways to detect packet loss deep in a provider's network that is several hops away? With multiple providers peered over BGP on our Internet edge routers, I need to be able to ...
4
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2answers
3k views

OSPF LSA Refresh Time

Is there a Cisco command that would allow one to modify the default value of 1800 seconds (30 min) for the OSPF LSA refresh rate?
18
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3answers
27k views

How do you know if a Cisco switch is handling traffic well?

I have just read Jeremy's question about 2960-S and iSCSI traffic handling, which drove me to ask this question: We all have lots of switches deployed in distinct infrastructures, how can you know ...