TCP Window Scaling // Windows vs Linux // Crazy Performance Difference Networking |
- TCP Window Scaling // Windows vs Linux // Crazy Performance Difference
- Network automation tools
- How to be more pragmatic with use of the "burden of proof" on network related issues?
- One handed Termination tool
- Puzzling OSPF Pathing
- AT&T Multipoint Control Unit Brochure from 1994.
- Does anyone have experience with a Calix ONT (E7) accepting double tags on ONT ingress?
- Juniper release numbers - 15.1X vs 18.1R etc.
- VLANs mismatch
- OpenDNS
- Nokia NRS1 and CCNA Lab Equipment List
- Need network suggestion for sending telemetry data from sensor/endpoint to local server
- SDA and Campus networks
- I work in this building. All sorts of cool stuff inside...!
- Fiber infrastructure mapping
- Perimeter firewalls and rapidly increasing internet bandwidth on offer from ISPs- how are you handling this?
- IOS-XR, ASR9K, BNG, and PWHE?
- Logging Traffic - Permitted and blocked
- Can someone enlighten me on circuit provisioning on the SP side of the house?
- I have a doubt about RA messages in IPv6
- Is there a future scope in cisco collaboration?
- Cisco WAAS + Windows 10..
- FMC Unresponsive
- Do you heat up all drops?
- ERSPAN on Nexus 3k only allowing rx
| TCP Window Scaling // Windows vs Linux // Crazy Performance Difference Posted: 30 Jan 2019 09:45 AM PST Hi, Two machines over a high bandwidth, low latency network. One is Ubuntu Desktop, the other is Windows 10. There's an iPerf server on the other end. The network is a 1gbps leased line. Same version of iPerf on both clients and server. When I run Ubuntu TCP iPerf, I receive ~900 Mbps which is what I'd expect. However when I run a Windows TCP iPerf, I get around ~50-100Mbps. Weird right? I directly connected this Ubuntu and Windows laptop together, and ran the test again: 1Gbps between the two, so I know both laptops are capable of achieving the speed. I wiresharked the test with the packet captures side by side: the packets are *identical* other than the Window Size Value, and it differs as follows: Windows - Window Size = 53248, Window size scaling factor = 4, Calculated Window Size = 212992. Ubuntu - Window Size = 229, Window size scaling factor = 128, Calculated Window Size = 29312. When disabling TCP Window Scaling on either machine, performance degrades. Really confused, no idea and have never seen anything like this. Anyone got any ideas? Edit #1: I have considered hardware / L1 issues, and all cables are tested etc. I spun up an Ubuntu VM in Workstation on the Windows machine (same machine getting slow speeds) and I achieved ~800 Mbps. [link] [comments]  |
| Posted: 30 Jan 2019 10:58 AM PST Hi, I am looking into tools to help automate network configuration, activation and maintenance type tasks. We've been using Ansible for a while and it's pretty good but looking to hear opinions on what else we should kick the tires on. Interested in API and GUI options that engineers could use. Itential was on my list but it's relatively new so I'd like to hear if you have any feedback. I don't work for a vendors just a network guy looking at ways to move beyond the CLI. Thanks [link] [comments]  |
| How to be more pragmatic with use of the "burden of proof" on network related issues? Posted: 30 Jan 2019 02:54 AM PST Currently I'm in a role where any of our customers can contact us and blame the network for any issue with little to no evidence. They with ease are able to put the majority of the burden of proof on myself and team. This usually comes in the form of not understanding their network or topology or even path of the packet even though they are the local network admin. They will blame the network and require me to prove its not. Generally it ends up being a server or some other network device and rarely the network itself. Now don't get me wrong, I'm always happy to help buts it's getting to the point now where the hand holding is taking up huge amounts of time and my team is literally doing the remote admins job for them. To the point where we must spend an hour or so just determining what devices are in the path before we're even able to rule the device out. Does anyone have any techniques or tips on how to push back again this type of behavior? [link] [comments]  |
| Posted: 30 Jan 2019 01:14 PM PST Hello everyone. I work in the IT industry but was born with a radial plexus injury to my right arm and hand. This means that I have limited strength and mobility when utilizing my fingers on that hand. I can successfully terminate Cat5 cable but it takes me a long time. Anyone else out there that has a similar situation that has a found or built a tool to help? [link] [comments]  |
| Posted: 30 Jan 2019 07:23 AM PST Hi everyone. I've got a head-scratcher, and wondering if /r/networking can help me understand the behavior OSPF is exhibiting. The topology is here: https://imgur.com/a/MPRg3DO The hardware is mixed variety, Brocade, Fortigate and some Ubiquiti. I can't figure out why OSPF is routing traffic from Host A destined for R5 the way it does (green arrows), while a lower cost option exists directly from R2 to R4. Egress traffic from R5 back to Host A does utilize the R4-R2 path, just not inbound. I think it might be due to some inter-area nuances, but just can't seem to put a finger on it. Thanks for any insights! edit: some more info. Destination on R5 is 192.168.168.128/26. 'show ip route 192.168.168.128 detail' on R2:Interface 1/3 is the interconnect between R1 & R2. Edit 2: Full 'show ip ospf database' from Both R1 & R2: [link] [comments]  |
| AT&T Multipoint Control Unit Brochure from 1994. Posted: 29 Jan 2019 06:50 PM PST Found this in a desk today. On the back it noted future upgrades to 1.5MBPS would be available. Not sure if it's a fit, but though it was cool nonetheless. [link] [comments]  |
| Does anyone have experience with a Calix ONT (E7) accepting double tags on ONT ingress? Posted: 30 Jan 2019 11:42 AM PST Trying to create an svc-tag-action but trying to see if the Calix OLT can support a customer sending two tags as I use TLAN if they're only sending one. Is the change tag service tag action the way to go? [link] [comments]  |
| Juniper release numbers - 15.1X vs 18.1R etc. Posted: 30 Jan 2019 03:02 PM PST Hi, I have some trouble understanding Juniper Version numbering. I already read a lot in Juniper's knowledge base but it's still not clear to me. It would be nice if someone could give me a quick explanation. For example looking at newer EX switches the article about JTAC recommend versions lists 15.1X and 18.1R. I don't quite understand what's up with the X versions vs R version and why I would pick an X version or R version. I understand that R versions are simply numbered by year and release within the year so 18.1 is the first release of 2018. However I am not sure about the X versions. Is 15.1X based on 15.1R? And if so why does it exist in parallel to the R version and where are the differences? I saw that the 18R versions are supported for way longer than the 15X versions. Does this mean that X versions will be phased out? Is there a generally advice for a green field deployment on which software version to use? [link] [comments]  |
| Posted: 30 Jan 2019 02:37 PM PST sorry its late, i keep getting the same error, ive assigned 5 different vlans to 5 different ports. they're all set to access, none of them are on the same vlan as ive mentioned. does anyone know why i keep getting this error? https://gyazo.com/383419c9ec068b0fca8618a5724f58d0 - the error https://gyazo.com/a9127d4379382df45b179e49d25ab3fe- my vlan name+ ID [link] [comments]  |
| Posted: 30 Jan 2019 02:12 PM PST looking for opinions about openDNS. My company is thinking about going to Cisco Umbrella but I just found WebTitan. thoughts on the matter? We currently run a Cisco WSA as our web proxy filter. [link] [comments]  |
| Nokia NRS1 and CCNA Lab Equipment List Posted: 30 Jan 2019 02:10 PM PST I have been tasked by the power that be in my shop to put together a lab for our guys to work on getting their NRS1/2 and CCNA/CCNP certifications. This is for a large company that is an ISP so assume for a moment that were looking at a magic budget, build it for future generations lab. Does any one have any experience with this or ideas on what equipment we would want? I have a CCNA so I have some vague ideas for that but all the Nokia gear we use is in the ridiculous overkill range for what would be needed for the Nokia certs. [link] [comments]  |
| Need network suggestion for sending telemetry data from sensor/endpoint to local server Posted: 30 Jan 2019 11:23 AM PST I need to wirelessly transfer messages from node/sensor to gateway that would be at most 2km apart from each other. The message would go through gateway to local server. The main information here is I need to work with 40 endpoints (that are present in field) that are sending messages to the local server. Here are some requirements for the system that would be nice to have:
I have worked with bluetooth, LoRa and sigfox. Unfortunately none of them worked well either due to range or one-directional messaging capability. I am currently looking in to Haystack Dash7 and Symphony Link but their online community is quite small. I would like to know what other technologies within LPWAN or aside from LPWAN I can use that would fit the aforementioned requirements? [link] [comments]  |
| Posted: 30 Jan 2019 09:17 AM PST Can someone try to describe what problem SDA is trying to solve? Also what do they mean with 'campus' networks, why are they not called 'enterprise networks'? Somebody cares to explain a bit? [link] [comments]  |
| I work in this building. All sorts of cool stuff inside...! Posted: 29 Jan 2019 11:32 PM PST Most of you seem to enjoy the pictures I posted of the building I work it. It's old. Tons of old equipment, brand new pay phone, abandoned in place boilers, and an abandoned call center. The call center with the blue pillars is a newer one that was also abandoned so you could see the difference 11 years makes. Enjoy! [link] [comments]  |
| Posted: 30 Jan 2019 08:40 AM PST To preface- I'm new to my organization and this project got slammed on my desk. We have approximately 50 Excel workbooks containing all the fiber patch panels we manage. They are asking me to provide a simple solution to determine what devices are connected where (and what patch panels that device might go through). They also want some functionality where you can specify one point and get an output of its far end. I have a couple ideas using pivot tables in excel or an Access database. However, what do you use to document your fiber infrastructure? [link] [comments]  |
| Posted: 30 Jan 2019 11:00 AM PST I work for a VAR / MSP in the SMB / SME space. Over the past year or so we have seen some big jumps in bandwidth on offer from ISPs to our clients. The old average for our area used to be 25-50 Mbps for smaller shops, but now we're seeing 100 at a minimum in most cases, up to 400. Nearly all of these networks are designed with perimeter firewalls handling most if not all of their routing, VPNs, etc. The price difference between an NGFW that can do 50Mbps and 400Mbps is substantial (at least in re: to most businesses of this size). The best I've really got right now is the very honest answer of, "It comes down to whether you want more bandwidth or more security based on your budget", i.e. we can deliver 400Mbps on your budget if you don't run IPS anymore (or similar). This can be a bit of a tough discussion because most clients assume that more bandwidth is always the answer, and while I don't disagree with them it doesn't always align with their other requests. Even if they never utilize that actual amount of bandwidth, if they happen to run a speedtest and see lower they assume something is wrong. In a meeting with our primary NGFW vendor, they said they're experiencing the same growth issue where mom and pop shops are getting 1Gb fiber circuits and if they want to make use of that full pipe they're going to need a very expensive perimeter unit, and that's just not going to happen. So, who has been dealing with this and what was your solution overall? [link] [comments]  |
| Posted: 30 Jan 2019 05:24 AM PST I am looking at a network that currently operates a full VPLS mesh with BVIs terminated on two ASR9Ks acting as BNGs. The request is to migrate away from VPLS to PWE3, however every document I can find regarding BNG features and IOS-XR say PWHE is expressly not supported. does this mean I need separate chassis -- one to do BNG duties and another to act as PWHE? I can clearly see ASR9K supports PWHE...and BNG features...just not together? appreciate any clarity anyone with experience on this platform can provide [link] [comments]  |
| Logging Traffic - Permitted and blocked Posted: 30 Jan 2019 01:58 PM PST Do you log blocked traffic to the firewall? Or only log permitted traffic? Or is should all traffic be logged? Does it change if it's a office or dc firewall? Looking for best practices [link] [comments]  |
| Can someone enlighten me on circuit provisioning on the SP side of the house? Posted: 29 Jan 2019 04:36 PM PST I'm wondering what a circuit looks like, from end to end, on the provider side of the house. Basically trying to educate myself, so I can talk shop better in certain situations. So, for example, say Customer orders a 10 Mbps Internet Circuit from Provider. A few weeks later, eventually Carrier, who is the LEC for this circuit, and a different company from Provider, shows up, installs a Cienna box with a fiber uplink, and then feeds a single RJ45 copper port off that Cienna, that is our circuit. Some cases, Provider will come and put their own box between that Cienna box and ours (Customer's) CPE router. In other cases, it just directly connects to Customer's router. So... I'm well familiar with how this circuit looks on Customer's side. We set up our BGP or static route or whatever with Provider's PE-Router, usually the other side of either a /30 or /31 p2p connection. (Understanding that it's a virtual circuit traversing two different organization's equipment to get to said interface, but as far as our router cares, it looks like just a directly connected interface.) We configure a traffic shaper going egress on that interface. Ok, we ordered a 10Mbps circuit? We set the traffic shaper to like 9.8Mbps egress. That way we don't push 1Gbps of traffic and drop like 90% of our packets. That's all fairly simple. I'm just wondering from end-to-end how the configuration looks on Provider's and Carrier's equipment. I know the typical answer "it depends." Could be a bunch of different situations, I get that. What's one that you would say is the most basic or common. What I'm most interested in are the following:
Basically I'm just trying to understand how the magic happens when we get a circuit like that, and can only send 10Mbps and only receive 10Mbps on that circuit, and if we try to send faster than that, it gets dropped, and if somehow, either Provider or Carrier set something up wrong somewhere along that path and we try to RECEIVE faster than 10Mbps, some policer somewhere starts dropping packets. Thanks! I'm really hoping to get a very clear picture of what this looks like from end to end, hopefully even someone will be nice and draw a crude diagram even. Would be very enlightening. [link] [comments]  |
| I have a doubt about RA messages in IPv6 Posted: 30 Jan 2019 01:03 PM PST hey, I'm studying now and I had a doubt about RA message in IPv6. Are this messages something like DHCP? Because as I read, the info says that this messages are given to hosts with addressing information. [link] [comments]  |
| Is there a future scope in cisco collaboration? Posted: 30 Jan 2019 03:40 AM PST I have just graduated from engineering and started working in a small networking company. The company I work for are premium partners of Cisco, so I am getting trained in Cisco campus itself. When I started my training I thought I'll be trained in IP, but our project is on Cisco collaboration it seems, so I am being trained in Cisco collaboration (voice over IP, ccna voice). So my question is that I'm being trained on Cisco product and also their technology, will I have good future in Cisco collaboration? What if some day Cisco end these products (WebEx, IP phones), what will happen to my job? What do you guys think about this field? Please give me your suggestions and views. Thank you. [link] [comments]  |
| Posted: 30 Jan 2019 12:23 PM PST Hello fellow packeteers Recently, my organization has been running into a peculiar issue with WAAS acceleration. The machines which have been upgraded to Windows 10 will often give a "Page Cannot Be Displayed" error, even though the internet is working fine. When the internal SM module is disabled or wccp redirect removed from the interface, all traffic works fine. If you refresh the page a few times, it will eventually load. [link] [comments]  |
| Posted: 30 Jan 2019 12:12 PM PST FMC is running at 100% CPU usage and is unresponsive within VMware, can I just reset the VM with no issues or will there be any issues after that elsewhere [link] [comments]  |
| Posted: 30 Jan 2019 05:54 AM PST I'm curious how many of you heat up every drop in a building. Do you install enough switches to cover all drops, even if a percentage of those drops will not be used? We've tried both ways, and while we like having to buy fewer switches, we are finding it difficult to manage the workload from drop usage changes. When we've had our onsite techs make the cabling changes from patch panel to switch, the end result is some pretty gnarly cable management in our IDFs, as they don't always have the appropriate cable lengths in the right color (to follow our established convention). Ideas on how to manage this are greatly appreciated. [link] [comments]  |
| ERSPAN on Nexus 3k only allowing rx Posted: 30 Jan 2019 11:47 AM PST We're setting up a new security device and setting up the monitor session, all the examples I've seen show using "both" on the source but all i have is "rx" as below. How do I grab the bidirectional traffic? monitor session 2 type erspan-source erspan-id 32 vrf default destination ip x.x.x.x source vlan x,x,x, rx no shut EDIT: duh it's source vlan x,x,x no modifier needed ... EDIT2: actually still same problem .. [link] [comments]  |
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