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1500 questions
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votes
5 answers

traceroute doesn't print entire route sometimes

Monitoring my network I realized some time ago that traceroute used to print routes more complete than it is doing right now... and, right now, sometimes traceroute omits some devices. For example, this is a more complete traceroute, including my…
Leandros López
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7
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2 answers

How do the Application, Presentation and Session layers of the OSI model map to TCP/IP's Application Layer and vice versa?

I need to map TCP/IP protocols to the OSI model for some university test revision I am doing. I was wondering if it is generally acceptable to assume any OSI Level 7, 6 and 5 protocol will be transferred directly into TCP/IP's Layer 4 (Application…
Michael Morgan
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7
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4 answers

Website filtering via IOS

Our office network uses the 1921/K9 router along with SG300 L3 switch (and a few other L2 switches) all with base modules. If we wanted to block employees from visiting certain websites, what would be the best way to do it with the current…
lamp_scaler
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7
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6 answers

Raw IP communication?

I'm studying the difference between the protocols IP and TCP. IP is said to provide an unreliable datagram service whereas TCP provides a reliable bytestream service. Further, TCP works on top of IP. So my question is, can the protocol IP be used…
lukas irides
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7
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2 answers

Juniper SRX - No traffic after 17 minutes

This is really a strange problem. I am trying to install a Juniper SRX 220H as the gateway to replace my old Cisco router in my testing network environment. The simplified topology is listed below: ISP ----- ONT ----- SRX ----- Other devices…
Lingfeng Xiong
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7
votes
3 answers

ISR routers - difference between routed and switched ports

On a Cisco ISR router - would you say there are any benefits from purchasing an HWIC or EHWIC to connect to the next set of switches within the branch network? For instance. Lets say Gig0/0 and Gig0/1 are routed ports that come on a 2901. Is there…
knotseh
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7
votes
2 answers

Poison reverse example

Can you give me an example when poison reverse is actually necessary? Distance vector routing protocols employ split horizon with poison reverse to minimize the convergence time when a route is no longer available. The thing is that I can't think of…
Silviu
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7
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2 answers

Difference between CRC and input errors - show interface

The command "show interface fa0/1" prints the following output: What is the difference between "CRC" and "input errors"? CRC errors confirms that a frame error has occured, but what about "input errors"?
Birdman
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7
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2 answers

How Can I Easily Tell If My Network Has Power Over Ethernet?

How could I easily identify whether my network at my office is capable or is utilizing PoE? I have Cisco IP phones but I know some phones can operate entirely over ultra-low voltage. How could I look at my network set up and be able to identify if…
gh0st
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7
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4 answers

Can Juniper EX series switches terminate a q-in-q interface?

Other terms are stacked vlans, provider bridges, s-vlan If we purchased EX series switches, could they be configured with RVIs to terminate the double tagged frame? Or, will we require an MX series router? We get wholesale customers presented as…
rick
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7
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3 answers

Does authoritative DHCP server mean no static IP setting?

I've recently switched my Mikrotik Router's DHCP server to authoritative mode. It fixed several problems with some clients remembering bad IP addresses. But what would happen if I connected a device with static IP to the network? Will the DHCP…
Amunak
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7
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1 answer

What is benefit of using CBWFQ with fair-queue statement

I mostly seeing configuration of QoS queues based on CBWFQ, witch is tripped off by shaping map. Something like below example. policy-map test class test bandwidth remaining percent 20 random-detect dscp-based class test2 bandwidth remaining…
Daniel Blazek
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7
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1 answer

Configuring a password policy on Cisco IOS or NX-OS

I was wondering if it's possible at all to configure a password policy which enforces password complexity for locally defined accounts. I know it's possible for TACACS+ and RADIUS, but I need to know if it's possible to enforce such policy for…
Lucas Kauffman
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7
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1 answer

How do Endpoints in a TCP conversation determine their MSS?

I understand the MSS is the Maximum Segment Size, which is the size of the Payload TCP will send. I also understand that a "receiving" MSS value is suggested by both parties in a TCP conversation during the 3-way handshake, and both parties will…
Eddie
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7
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2 answers

dont fragment bit PING TOOL

Actually my machine wwan0 MTU is 1500 ashokkrishna@ashokkrishna-Lenovo-B560:~$ ping -s 1490 example.com PING example.com (93.184.216.119) 1490(1518) bytes of data. 1498 bytes from 93.184.216.119: icmp_seq=1 ttl=51 time=1119 ms 1498 bytes from…
ashok
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