Avery Abbott
  • Member for 8 years, 8 months
  • Last seen more than a month ago
  • Columbia, MO, USA
How can there be more than one MAC address on single switch port?
Accepted answer
19 votes

You can have more than one MAC address on a switch port if: You have a switch connected to it. Could be another managed switch (like a Cisco) or an unmanaged switch (like a consumer Netgear or ...

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Setting subnet mask to 255.255.255.255
14 votes

Yes, there's a problem. Your default gateway needs to be in the same subnet as your device. By setting the subnet mask to 255.255.255.255, you've told the computer that nothing else is in its subnet....

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I want to perform monitoring of my network infrastructure, can this safely be done with SNMPv2?
9 votes

Whereas SNMPv3 is significantly more secure than v2, you can at least mitigate some of the risk of implementing v2 by restricting access with an ACL. I would also advise against creating a read/write ...

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BGP vs OSPF path selection with /24 vs /23`
7 votes

Most specific match (longest subnet mask match) will win regardless of routing protocol. If the subnet masks are equal, the route with the lowest administrative distance wins. In this case eBGP ...

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Does IEEE 802.11ac imply Wi-Fi Direct compatibility?
Accepted answer
6 votes

The answer is no, the two are separate technologies. 802.11ac is the next generation of wifi, one step passed 802.11n. WiFi-Direct is just an on-demand autonegotiated ad-hoc wireless network. It could,...

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Rolling Stack Upgrade on a Catalyst 3850
Accepted answer
5 votes

Nope, sorry. That's why I prefer daisy-chaining to stacking, even though I lose out on some bandwidth and a couple of ports. There are some helpful hints on the upgrade here, though: https://...

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High Availability on Routers - HSRP, VRRP, GLBP
Accepted answer
5 votes

It's all about the timers. There's an advertise interval and a master down interval (hello and hold time in HSRP and GLBP). The master sends VRRP advertisements according to the advertise interval. ...

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How to allow DHCP Client to switch to an identical network on a different subnet without losing TCP/IP
4 votes

Not with different subnets, no. You can use the same subnet, same VLAN, and same SSID on both APs and you'll be able to roam between them. If you try to use a new subnet, the client will need a new ...

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Packet Tracer: Ethernet interface up/down
Accepted answer
4 votes

All the PT-jabbing aside, this is just a strange Packet Tracer behavior and does not match the real world. On a real switch, an unplugged ethernet, fast ethernet, or gigabit ethernet interface would ...

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Connecting two different Cisco Switches using Fibre
4 votes

Multimode fiber has a bigger core and uses less precise optics than singlemode fiber. This makes the transceivers (SFPs in your case) cheaper than their singlemode counterparts. This also means they ...

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Is DTP enabled by default on the newest Cisco devices?
3 votes

The newest small campus access switches are 2960X switches, and they still have DTP enabled by default. Nexus switches are designed for datacenter use, not for user-facing ports. DTP is also enabled ...

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Dell R720 and Cisco 2960S SFP+ connection
3 votes

SFP+ = 10gig SFP = 1gig Most SFP+ ports will accept an SFP transceiver SFP ports cannot support SFP+ transceivers You might be able to connect a 1gig link from the Broadcom to your switch (if the ...

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Could MD5 digest be synchronized between VTP Server and Client if there is a discrepancy in Switch Versions?
Accepted answer
3 votes

The basic answer to your question is no, the different switch versions don't matter. As long as you're running the same VTP version on the server and client, both are configured for the same VTP ...

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Connect one router to layer 3 3750-X stack for redundancy
3 votes

You'll need another physical interface on your router that runs at the same speed as your existing physical interface. Once you have that, you can create an etherchannel/port-channel/lag between the ...

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Help with BGP configuration
Accepted answer
3 votes

A will learn C's routes directly through eBGP. A will learn D's routes through B using iBGP. A will prefer C's routes because they were learned through eBGP. B will learn D's routes directly through ...

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No auto-negotiation for X520 with 10G direct attach cable?
3 votes

I'm not sure about the IEEE standard, but Avaya switches only support autonegotiation for 10/100/1000 Mpbs. Autonegotiation isn't supported for 10 Gig connections. This guy breaks it down a little ...

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Changing Label for Generic PC in Packet Tracer
2 votes

Two options: Single click on the computer's name. A text box might pop up (worked intermittently for me in 6.2) where you can input a new name. Click on the computer, go to Config, and change the ...

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IS-IS Hello packets and IPv4/IPv6 addresses
2 votes

It is typically the IP address tied to the physical interface, but not always. JunOS from Juniper, for example, sends the Router-ID which can be a loopback and not tied to a physical address. Source:...

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How to Ping from a Cisco IP Phone 7945G?
Accepted answer
2 votes

Per Cisco's documentation, they recommend you place a workstation in the same VLAN as the phone and use that for ping, etc. "Determine if you can ping the Cisco CallManager server from a device on ...

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Cisco 2950 switch LED off timeout
2 votes

Looks like a hardware fault. This is not standard nor accepted behavior. I'd agree with Mr. Lock and test your cables. Beyond that, try re-loading the IOS image on the switch. If all of that fails,...

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ipv6 Aggregatable global unicast addresses
2 votes

RFC 2450 - Proposed TLA and NLA Assignment Rules Microsoft's is in line with the proposed IETF RFC 2450. Since it's still proposed, it isn't finalized, but it's the likely end format.

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On a wired LAN of 2+ computers, can you securely provide wireless Internet to one and not the others?
Accepted answer
2 votes

1) Yes You can connect a computer to two networks. The practices is commonly called "Dual-homing" and requires a bit of a trick to make it work. Your computer that's on both the wired and wireless ...

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Is it possible to run CME in a Cisco 1812
2 votes

http://tools.cisco.com/ITDIT/CFN/jsp/index.jsp http://www.cisco.com/c/en/us/products/routers/1800-series-integrated-services-routers-isr/index.html Doesn't look like it. The only 1800-series Cisco ...

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Behavior while chasis clustering between SRX650
Accepted answer
2 votes

If I understand your question correctly, you are at least partially right. For HA failover, you'll need the same ports to have access to the same VLANs. You'll need to trunk VLANs 172 and 192 ...

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BGP, multipathing, and possibly OSPF
Accepted answer
2 votes

This might be a bit long winded, but I'll try to address most of your issues in one go. Wish me luck! You can have your upstream service providers advertise a default route (0.0.0.0) through BGP to ...

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Mixed stack IOS upgrade - Cisco 3750x,3750G
1 votes

Your process is correct, and assuming you get the same version number for all of them, you should be fine. If you're connected to the stack master, a "dir" should show flash file systems matching ...

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Finding the Ip address of a pc hogging the bandwidth in a switched environment
Accepted answer
1 votes

Assuming you still have a port open on your SG300, you can use port mirroring/SPAN port to send a copy of all the traffic currently going to your router out another port. Then you can attach a ...

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Difference between Mobile hotspot and Router
Accepted answer
1 votes

Your cell phone has two primary connection methods - wifi and cellular. When you're connected to a cellular network, your wifi is not in use. Enabling hotspot turns on our wifi and allows you to ...

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How does information move on a topology bus network?
1 votes

I'm no expert on bus topology, but I'll do my best to answer this: All frames/packets in the bus network will have a source and destination address. All systems in the bus sniff every frame and ...

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Load Balancing System For 2 Servers on Different Datacenters
1 votes

What you need is a DNS server that does health checks. There are both on-prem and hosted options available from multiple vendors. These can serve up DNS responses based on (among other things): ...

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