How A Device Knows To Slow Down Broadcast Of Traffic
Feb 4, 2012
how a device (PC or router, in this example) knows to slow down broadcast of traffic.Say my cable modem from my ISP is coded to only allow 50mbps.My internal network supports the normal 100mbps.How does my router know to not send my cable modem more than 50mbps of data (because anything above, I assume after the cable modems RAM fills, will be dropped).I know TCP/IP has "Autonegotiation" which determines link type, but it's only based around if t's 1000/100/10 ethernet. No custom speed variable, such as 50mbps in this case.Say I put my network uploading data maximum stress to my internet connection, at 100mbps. Will my cable modem ever send some special packet telling me router that's too much or something?I suppose if I knew this, I could also understand how when I upload a file to another computer on my network, it does it at the full 100mbps, but over the internet, limited to my upload speed; but how does my computer or router know to slow down because my ISP doesn't allow 100mbps up? It has to be able to detect link speed somehow, otherwise just constantly sending 100mbps up will result in tons of lost data at my router/cable modem, and give the computer a frequently false sense of upload speed.
View 1 Replies
ADVERTISEMENT
Aug 22, 2011
we manufacture an industrial device that runs embedded linux, and we are throwing ideas around on how we can find devices that are connected to our network, without knowing their ipAddress. I know this is possible, because Advantech do it with their ADAM utility to find units. I put a WireShark sniff on my LAN as the ADAM Utility found a unit, and saw the following[CODE]
View 2 Replies
View Related
Sep 22, 2011
I require a system that will support 3 VLANs, the VLANs are purely for containment of broadcast traffic and needs to support inter-VLAN communication between client devices. Would the following configuration work:
Port based VLAN on the SRP527W with each port connected to layer 2 switches serving each VLAN.
DHCP server on the SRP527W assigning IP addresses for each of the V LANS in different ranges. (eg 10.10.1.xx, 10.10.2.xx, 10.10.3.xx). Would there be any benefit upgrading the Router to a SRP547W?
View 2 Replies
View Related
Feb 23, 2012
We have 2 switches split across 2 datacentres connected via an interconnect. Over the past couple of days the interconnect provider's Cisco kit has shut down our port (err-disabled) due to a broadcast storm. They had the level set at 1 which I thought was a bit low. They say they tried to set to 2, then 5 but still kept tripping the storm-control feature so they set at 10. They say they've always had it set at 1% (on a 100Mb switch) and so we must be generating more broadcast traffic.
I'm trying to identify where the broadcast traffic is coming from. On our Cisco 3750 I've clear interface counters and when I do a sh run | i broadcasts there are a few ports which have what seems like a high broadcast count. The one port that is especially high and the only one tripping the storm-control feature (I've enabled on all our ports to try to identify where the traffic is coming from) is the port connected to the 100Mb interconnect. I've mirrored that port to another port and connected a server with wireshark so I can capture all the traffic across that port.
What I'm struggling to find is the source of the broadcast traffic.I have a few questions are these broadcasts layer 3 or layer 2 broadcasts. Also in the output below when it says broadcasts received is this inbound to the port i.e. from the connected device or is this a total of inbound and outbound broadcasts.
When I use wireshark and filter the capture on broadcasts (ff:ff:ff:ff:ff:ff) I see only 200-300 compared to the thousands the switch is reporting.If I filter on the broadcast IP address I also don't see the numbers corresponding to what I see in the show interface output.
GigabitEthernet1/0/1 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 0014.a93f.7401 (bia 0014.a93f.7401)
Description: Interconnect
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 4/255, rxload 44/255
Encapsulation ARPA, loopback not set
[code].....
also I'm currently doing : monitor session 1 source int g1/0/1 both, and also tried just rx incase I just need to be looking at receive traffic but still nothing is standing out.
View 10 Replies
View Related
Jan 31, 2012
Our network feels slow and trying to find the best way to investigate this properly. We have Cisco chassis 4500 with mix of 3560/2950 Edge switches 1GB backbones and WLC/WCS in place. The network is broken into multiple V LANS and IOS on our switches haven't been updated in 3-4 years.
On a wireless laptop (G) with get throughput of 1-2MB/s transfer speed with usually 10 clients per AP and LAN we get anywhere between 7-15 MB/s transfer. Using wire shark on a wireless laptop we see a lot broadcast traffic from other clients and the same for LAN. What is the best way to troubleshoot performance issues on the network and where do I start?
View 1 Replies
View Related
Dec 17, 2012
How do I limit broadcast/mulitcast traffic on a switchport to e.g. 5000 pps ? I don't want the port to shut down, just block or drop broadcast traffic that exceeds 5000 pps.
View 19 Replies
View Related
Jul 5, 2012
We run a network of several 2960G and 3650G switches in a network with a number of VLANs. One one particular VLAN (let's call it VLAN 10) it appears that non-broadcast traffic (i.e. normal unicast traffic) is being copied to every port in VLAN 10 only on one switch . The traffic is not crossing trunk ports and does not appear on other switches that have ports in VLAN 10. We first spotted this by noticing that a UPS port had an unusual amount of activity on our port througput graphs:
This traffic at 4 am is not expected and this profile is repeated across all ports in VLAN 10 on this switch (a WS-C2960S-48TD-L stack running IOS 15.0(1)SE3)\iffed one port using local SPAN (the UPS port) and discovered that this traffic was not broadcast, which was running at a normal low rate at all times. The traffic appeared to be unicast traffic from other ports of the sort you might see on a hub. It was from various hosts that live on VLAN 10, most (not all) of the conversations had one end station homed on the 'problem' switch. There are about 800 non-broadcast packets per hour and this is a busy VLAN so it does not account for all the traffic on the VLAN.
View 3 Replies
View Related
Apr 5, 2012
I have a media player wired to my dir-655. I have a wrt300 on the same network to use for vpn. I live in Canada, and to use Netflix etc, from the US, I need to use the vpn.Is it possible to have the media player routed through the wrt300, rather than discovering all the IP addresses for Netflix etc and routing each one?
View 3 Replies
View Related
Oct 21, 2012
I just reformatted my PC and the internet is really slow. I should be getting 15 Megs down but only getting as little as 1 Meg down. Every other PC and device in the house is getting 15 down. why my PC would be slowing down my speeds?
View 1 Replies
View Related
Feb 12, 2013
I have reconfigured the router from scratch using all sorts of methods and can not work out whats wrong, basically when the client is going to their bank the login screen takes upto a minute to load, and the same with hotmail. However using a cheap billion router these login screens are instant
Checking the CPU usage shows the CPU is hovering around 5-20% at the worst of timesThere is about 10 machines behind this router and they do not do that much intensive work over the link besides Outlook Anywhere (HTTPS)I have put a ACL on the LAN connection to only allow 1 machine in and still no luckI have also updated the IOS to c870-advipservicesk9-mz.124-24.T4.binAll other traffic runs fine over the link and there are no complaints on standard HTTP traffic
View 3 Replies
View Related
Jun 8, 2011
I got a stange vpn problem, just added a new vpn tunnel to our ASA5510 and then the users report that the traffic through the tunnel is very slow, when I try it myself I get a speed like 50kb/sec to the internal server.If I use our regular tunnel or any other tunnel the speed is just fine. I´ve added the new tunnel in the same way as the other tunnels, that is thorugh ASDM vpn wizzard.
View 2 Replies
View Related
Feb 15, 2012
I am using virginmedia superhub which is supposed to give me a max of 30mbps. I use it wireless but am often getting fluctuations in speed - sometimes 500kbps upto 20mbps, nothing consistently close over 20mbps or close to 30mbps. I have bought a powerline kit - "develo olan 200 AV Wireless N" which has improved the speed but I still get fluctuations.
View 1 Replies
View Related
May 2, 2013
We have many VPN tunnels back to our corporate office. All of these tunnels are very slow (same with our client VPN's). Our main firewall device at the corporate office is an ASA5510. We have a 100 Mb/sec Metro Ethernet internet connection here. We do not allow split-tunneling.
Our remote sites vary. We have DSL connections, cable internet connections, and other types of broadband that vary in speeds from 5 to 100 Mb/sec (up and down). The remote sites mostly have PIX 501's, but we have an ASA 5505 in one of the locations.
To take an example. On one of our remote sites that has a 100 Mb/sec connection, if I ping device to device, I'm getting ping times of about 50ms. And I'm pinging back through another 100 Mb/sec connection. If I get on a computer down there and run a speed test, I'm showing down speeds of about 1.5 Mb/sec... nowhere near 100. Some of that could be due to the lack of split tunneling, but I also suspect this could be an MTU issue.
Right now, all my MTU's are just set to the default 1500. Perhaps this is too high. I used this site to check my max: [URL]
I did a few tests from behind several of my firewalls. I pinged from a machine on one side of the tunnel to the firewall on the other end. I'm assuming the max MTU I come up with is the max MTU for the firewall I'm behind while pinging, right? The max amounts I came up with for some of my devices were as follows: Corporate ASA 5510 > 1272 (if you add the 28 byte packet header that would make it 1300) Remote PIX 501 > 1416 (if you add the 28 byte packet header that would make it 1444) Remote ASA 5505 > 1418 (if you add the 28 byte packet header that would make it 1446)
So, do I just need to set my MTU values to the appropriate amounts? I have tried changing the value, but I don't see any change in speed/performance. But I also don't know if I need to reboot the firewalls after changing the MTU. I know with Catalyst switches, you have to reload. But I didn't see any messages about needing to reboot on the ASA's/PIX's.
View 10 Replies
View Related
Jul 15, 2012
I have 2 new 3750g devices in a small environment. switch1 acts as our collapsed core and has ip routing enabled, and is connected to a ASA 5510. There are 3 HP l2 switches connected to switch1 as well. switch2 is simply a server switch. switch1 and switch2 have a 2port etherchannel between them, and a vlan trunk carrying 4 vlan's. traffic between any 2 hosts on switch2 (same vlan) are slow. (average 300Mbits/sec) If I move one of those hosts to switch1, speeds increase by 3 times. (average 900 Mbits/sec). Additionally, traffic between any 2 hosts on switch1 are quick. testing is done with iperf as well as timing 1gig file transfers.
I don't see any errors or drops anywhere, and there are no other symptoms other than slow transfer beteween hosts on switch2. I just got 2 more of these 3750's to put in a 2nd site that we have, put a quick configuration on them, and have the same result. Other than switch1 having ip routing enabled, the configs are pretty much identical.
View 2 Replies
View Related
Dec 20, 2012
In my LAN environment, I'm using two cisco SG300-10 switches. Both switches are connected by GE10 on both switches, where both ports are set to trunk.Now on all ports 1-9 on both switches, I'm having client computers attached. So I set ports 1-9 to "access" mode.All interfaces on any switch is left in default vlan.
Is it normal that I see all traffic from all connected devices on any port where I connect a listening device?What I'd like to achieve is, that only traffic that is meant for a specific workstation is actually forwarded to this workstation. By now it seems that I get all the traffic from everybody.
View 6 Replies
View Related
Jun 8, 2011
I have installed CSC-SSM-10 on cisco ASA 5520.I am facing two problems
1 : When I send traffic from ASA to SSM module then internet connection becomes slow and sometimes internet session disconnected.
2. When I try to manual update then following erros shows please see attachment .
View 6 Replies
View Related
Nov 30, 2011
My BEFSR81 is my primary router and has DHCP turned on. The router's DHCP range is set to accommodate 12 devices. I have three computers wired to it and their Host names (as specified in the set-up of each computer) show up in the router's DHCP device table. I also have two printers (one old Brother HL5250DN laser printer and one new HP Photosmart Premier C410a inkjet printer) connected and there are blanks where the Host name should go. I would like to be able to tell which printer is which when I am looking at the DHCP device table. How can I get a names associated with each printer's IP address in the router's DHCP device table? (The real problem is that the router seems to have both printers at the same IP address (192.168.1.100) and if I can get one of them to change I'd like to know which one it was!)
View 1 Replies
View Related
Jan 3, 2013
We are using LMS 3.2.1 with SP1 and Campus Manager 5.2.2.Server runs Windows 2003 R2.Everything runs fine except for User Tracking on two Catalyst 6500 switches running CatOS. These devices are discovered, reachable, SNMP works fine, neighbors seen. But when we try to launch acquisition, the UT utility complains with this error message:"Failed to start acquisition: Device unreachable. Please enter a valid device."When we wanted to add ports via Device Trap Configuration, LMS has fired a different error message: "There are no ports to configure for the selected device(s).Check whether you have selected any router(s)." I have checked the portsData.xml file, which doesn't have any ports included for the two devices: [code] We have tried to exclude / include the switches in the data collection, but that didn't work.
View 3 Replies
View Related
Feb 11, 2013
The problem: I need to track a bus from city to city in real time.I'm thinking of a gps device without screen or apps, it only sends the current location to a server. Is this possible? What device can be useful?
View 1 Replies
View Related
Apr 14, 2013
I know that 255.255.255.255 is the broadcast address to send message to all hosts that are in LAN. what i want here is, i want to send a mail to all hosts using this address.
View 9 Replies
View Related
May 28, 2012
Is it normal for a pc to send broadcast to ip address that don't really exist? I am using wireshark to sniff my company's network activity and im seeing something like this.who has 192.168.2.102 tell 192.168.2.235
who has 192.168.2.103 tell 192.168.2.235
who has 192.168.2.104 tell 192.168.2.235
who has 192.168.2.105 tell 192.168.2.235
who has 192.168.2.106 tell 192.168.2.235
but ip address 192.168.2.102 - 192.168.2.106 are currently not being in use..
View 5 Replies
View Related
Jul 5, 2011
I'm trying to get a wireless N-router and a N-adapter for a room outside the range of a G router. But their are two laptops at the house. They both use g adapters. Can the N router broadcast both N and G signal at the same time? So all adapters in the house can connect to the router. Does broadcasting both signals degree the range of the N broadcast making the an additional N adapter useless?
View 4 Replies
View Related
May 16, 2011
My router has been having major problems lately [Well, for a while now]. Before, it would make all my machines [1 PC, 2 Laptops] disconnect from the internet briefly and reconnect. This doesn't impact browsing, video watching, etc. It wouldn't even say I was disconnected. However, I know it was disconnecting because programs like AIM, MSN, and multiple video games would say I lost connection. For example, MSN would disconnect and take me out of any conversations and reconnect a second later. Friends tell me that I keep going offline and then online.
I read somewhere I should change my channel, so I did and still got the same problem. Furthermore, my router/pc are literally right next to each other. Then I read elsewhere I should do a factory reset on my router by holding the reset button for a while. So I did and it reset. It started broadcasting as an unsecured network, so I was going to secure it.
1. Log in via http://192.168.0.1 (default "username: Admin and no pass")
2. Go to setup tab ----> internet ----> internet connection wizard2.1 CHANGE PASSWORD ! click next 2.2 chose time zone (you know where you are) 2.3 Configure your Internet Connection DHCP Connection (Dynamic IP Address)Choose this if your Internet connection automatically provides you with an IP Address. Most Cable Modems use this type of connection. 2.4. press "clone your computer's MAC address" ; hostname: 'your computer name in ubuntu' ( mine is "grobar" yours is ..... )
3. Go to setup tab ----> wireless settings ----> Wireless Network Setup Wizard (after this we're gonna do manual settings)
3.1 give your network a name= SSID (e.g. 'grobar')
3.2.Automatically assign a network key (Recommended) and chose WAP or WAP2
3.3 Write down the network key!!! Or do printscr and save this page.
4. Go to setup tab ----> wireless settings ---->Manual Wireless Network Setup 4.1 Wireless Network SettingsEnable Wireless : ALWAYS Wireless Network Name : (Also called the SSID) the name you gave in 3.1 802.11 Mode : chose "mixed 802.11n,g and b" Enable Auto Channel Scan : YES Wireless Channel : AUTO Transmission Rate : BEST (Mbit/s) Channel Width : AUTO 20/40 MHz Visibility Status : !!!Invisible!!! (so that no outsiders know your SSID except you) So after I finish the Internet Connection Wizard [Setting up Password etc], the http://192.168.0.1/ page asks me to click "Connect" so it can reboot the router with the settings. When I do so, the router turns off with the power icon being orange. After about 15 seconds or so, the broadcasting icon, power icon, and PC1 icon all turn green. However, there is a globe icon on it as well and that is ORANGE.
Regardless of power cycling, redoing the process, etc. it stays orange. None of my machines can connect to it. The only way I can connect again to the router is if I do a reset again (By holding the reset button). But then, I am unsecured and live in an apartment. I would like to add that the above process is the one I did previously and it worked fine. But then I had to reset the router and a similar problem occurred but I managed to fix it somehow and the first problem I talked about started happening (Reconnecting and disconnecting). Furthermore, when I go to "Connect to a Network" one of the old SSIDs I created for the router is still there regardless of the router status (Offline, Not connected, etc). I am typing this by connecting my PC directly to my modem. Router Information: D-Link DIR-615 300N
View 4 Replies
View Related
Aug 30, 2012
I am having issues recieving UDP response from my smart lighting control, i can here it in the same town but not from overseas..internal ip address 192.168.0.3 port 6000 it hears my commands from overseas i just cant here its response.
View 3 Replies
View Related
Mar 31, 2012
I am considering a toshiba tv with wifi. i want to limit the cables up the wall and would like to broadcast my cable to my tv by wifi
View 2 Replies
View Related
Aug 12, 2011
my wireless router isn't broadcasting. It has the normal internet up but the wireless isn't allowing us to connect at all.
View 1 Replies
View Related
Sep 29, 2011
My D-Link DIR-655 most of the time does not broadcast wireless signal. I use Windows 7 and XP with same result. I see at least a dozen of broadcasting wireless signal in my network. Even after it worked, then next time I power-on PC, the signal is not there. The Router does not show the status light for wireless usage for these non-broadcasting time. It works and does not work.
View 2 Replies
View Related
Apr 25, 2012
I have an DLINK-dir 815 router.. I have tried for 10 hours to get broadcast IP to work, no luck.. All html/javascript modifications.
The WOL works on LAN, but not over internet, so I figure it's the broadcast IP that needs to be virtual servered
View 1 Replies
View Related
Dec 2, 2010
I have my DIR-825 (type B, .202NA FW) all set up and wireless is working well, EXCEPT for the fact that inSSIDer consistently shows it broadcasting at only 54mbps, while it also shows several of my neighbors in the 150 and 300 ranges. I'm using a DWA 160 adapter in my notebook.
I have my 2.4 channel set for g&n, and my 5.0 channel at N only. both WPA2 and AES. WMM enabled. I've tried any number of combinations but nothing seems to work.
If I was content with 54mbps, I'd have stuck with my old G router.
View 5 Replies
View Related
Oct 8, 2012
Why do we need them? Could we leave the LAN with a subnet broadcast packet (for instance with an address of 192.168.1.255 /24). Are those addresses used for something?
View 4 Replies
View Related
Mar 14, 2013
Trying to find out if a switch learns a mac address of a connected device which only sends broadcasts to the switch port (no unicasts). For example one type of attendance terminal...
View 14 Replies
View Related
Feb 26, 2012
They currently have three Ambicon WL300N-ARs in their network. They are set up as AP and everything has been running fine till we tried to put a security DVR/camera behind each router. The first one worked without any issues but once we connected the second DVR to the network became unusable, very slow. Someone told the IT guy that it was probably a broadcast storm. I don't know anything about the ambicon routers, but if the wireless is setup as a AP would it forward broadcast? I was under the impression that routers did not forward broadcast. or by setting it up as a AP it no longer performs as a router? The three Ambicons are connected to a unmanaged fiber switch, I asked for a make and model but he didn't know. Also connected to the fiber switch is another unmanaged netgear switch.
View 1 Replies
View Related
Jun 27, 2012
I have an AP, model AIR-LAP1041N-A-K9. How does the AP work? How does the AP broadcast?. Is It a circle and the AP is the center? Does the AP broadcast more front than back? Have any blind spot? I see the datasheet [URL] -
Integrated Antenna
#• 2.4 GHz, gain 4.0 dBi, horizontal beam width 360°
View 2 Replies
View Related
