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1500 questions
13
votes
4 answers
Minimum ethernet frame is 64 bytes, Why the payload must be padded to at least 46 bytes
What is reason to pad payload to mininum 46bytes, to form a ethernet frame of 64 bytes.
Following says min would be 41 bytes.
https://stackoverflow.com/questions/14526139/what-is-the-minimum-packet-size-for-tcp-over-ipv4
I could not connect the…
Vasu
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13
votes
3 answers
Wifi TCP iperf throughput: 1 stream vs multiple streams?
In a WLAN iperf TCP throughput test, multiple parallel streams will give me higher throughput than 1 stream. I tried increasing the TCP window size, but I still cannot achieve the max throughput with just 1 stream. Is there something else in the TCP…
elin05
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13
votes
3 answers
Two-factor authentication for SSLVPN (cisco)?
Just got asked today about implementing two factor authentication for users of SSLVPN within our company (connecting via Cisco AnyConnect we don't support/use WebVPN). Currently we use LDAP for authentication.
I've identified a company that…
A L
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13
votes
3 answers
Tracking down an invalid source mac address
I have inherited support of a remote site which contains a Cisco 4500 and is connected to ~2 dozen cisco access switches - primarily 2960s with a couple of 3750s and 3560s. Not all access switches are directly connected to the 4500 - there is some…
User123456
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13
votes
2 answers
VPLS Multihoming on Junos - FEC confusion
I'm going over the VPLS multihoming options on Juniper's web site. I'm not concerned with LAG and MC-LAG for the moment.
As far as I'm aware:
FEC128 is when you are using manual discovery of pseudowires (LDP)
FEC129 is when you are using BGP…
mellowd
- 3,834
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13
votes
4 answers
What layer of the OSI model does NAT work?
Simple question and the answer is layer 3 of course, but can we say that PAT is working on layer 4 also because it deals with port numbers which is a layer 4 function?
Or is it only a layer 3 protocol?
aia87
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13
votes
1 answer
JunOS: Password recovery has failed
I am trying to recover a root password on an MX80 but I'm receiving some errors and have no idea what they mean (it's not live so suggestive "disruptive" steps is acceptable);
The steps I have taken are as follows;
Reboot the router, at the prompt…
Baldrick
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13
votes
1 answer
Point Of Presence vs. Central Office
What is the difference between these two (in distance and function)? I understand that a Central Office is a place where the ISP stores equipment that connects many clients. But the POP has a similar definition. It is a place where many clients…
BrunoMCBraga
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13
votes
3 answers
OSPF Stuck in Exstart Adjacency State
According to this article two routers will get stuck in the exstart adjacency state when their configured MTU sizes do not match. Does a VLAN tag affect this as well even if the routers involved are unconcerned with which VLAN the packet is coming…
JDGray
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13
votes
2 answers
Are there any global network other than the Internet?
I found this definition of Global Networks:
Currently does any Global Network exists (apart from Internet)? Can someone Quote some examples? Or non-global but on a country-wide scale(ATM network maybe)?
Doesn't every other WAN network comes under…
Jarwin
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13
votes
4 answers
Raw-Ethernet Frames
Recently I was puzzled by the following articles about Raw-Ethernet frames:
RAW ethernet vs. UDP
Message Passing Using Raw Ethernet Frames
Briefly, both of them discusses that it is possible to establish a point-to-point communication using only the…
Mark Messa
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13
votes
3 answers
I want to perform monitoring of my network infrastructure, can this safely be done with SNMPv2?
I need to perform monitoring of my network infrastructure but I'm wondering if using SNMPv2 is secure? What are the weaknesses of SNMPv2?
Lucas Kauffman
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- 51
13
votes
2 answers
What purpose is the Uplink port in layman's terms and do I need it?
I have an old Linksys switch (EZXS55W) and it has worked fine for many years now, but I tried to hook something up today to the last open port and noticed the device didn't work when I did this. When I looked about my switch, it says that it…
Vistance
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13
votes
2 answers
Open a range of TCP ports in Cisco IOS NAT
ip nat inside source static 192.168.1.10 10.10.10.9 route-map RANGE
!
route-map RANGE permit 100
match ip address 102
!
access-list 102 permit tcp host 192.168.1.10 range 3000 3389 any
The configuration does not seem to work.. just creates a one…
Luna
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13
votes
2 answers
Simulating a poor network
I'd like to set up a poor wifi network in my office for developers to test on. What is the best way to simulate real world crappy wifi? High latency? Dropped packets? low bandwidth?
SAR622
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