Questions tagged [router]

For questions about network routers, devices that forward data packets between computer networks, commonly at the network layer (layer 3) of the OSI model.

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4
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1answer
362 views

Which physical interface would be used to send/receive packets intended for a loopback interface?

Let us say, I have configured the managed router with a loopback addresses - Interface IP-Address OK? Method Status Protocol GigabitEthernet0/0 ...
2
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1answer
66 views

Is a new Frame created between Routers and also Hosts

Trying to understand how frames are structured between hosts and routers. My basic understanding is that a new frame is required to encapsulate a packet from each router. Example being, if you have ...
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3answers
775 views

Collision domain question

I'm studying for my CCENT exam, and not quite sure why the book (official Cisco) says that there are 5 collision domains in this example. Isn't it supposed to be 4? The hub on the left, the hub in the ...
2
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1answer
85 views

Bonding and switching between 2 different Links/WANs/Interfaces

Before I ask anything, I'd like to say that I pretty much searched a lot (to what I know of from keywords and terms such as "bonding" "wans" "links" "failover" "aggregate") and I couldn't find any up ...
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2answers
58 views

How does a router logically process packets going into and out of the DMZ?

I wanted to ask this question because of the fact that through CompTIA Network+, I learned that internet exposed services/servers/devices are to be placed in the DMZ like email servers, DNS servers, ...
2
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1answer
510 views

GNS3 Routers - what is the difference beteween line con 0, line aux 0, and line vty 0 4?

Totally new to this and am not sure what the difference between them are. Can anyone explain this to me in simple terms??
4
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4answers
294 views

Do I need to add something to support inter-VLAN communication?

In my network using Cisco router/SW C1111-8p, the native VLAN 1 is not connected and doesn't have IP. VLAN10 192.168.10.1/24 with vlan10 DHCP pool VLAN20 192.168.20.1/24 with vlan20 DHCP pool Both ...
2
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1answer
551 views

What do I need and where to setup 2 VLANs with a Cisco router 1100 series with a wifi AP Aironet 1300 series

I am struggling and I don't really know what I need to setup my network. I have a Cisco router C1111-8p (8 switch ports) and a wifi AP C1832. +---------------+ +---------...
5
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2answers
86 views

Cisco 2821 hangs with “No memory”

I have one (pretty old) 2821 router, running BGP with 2 ISPs. (C2800NM-ADVENTERPRISEK9_IVS_LI-M), Version 12.4(24)T5 Sometimes for unknown reason it just hangs, and as it is remote location I cannot ...
2
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1answer
116 views

RV260W as Access Point

We recently upgraded to a proper firewall, with some help from this community, and are now looking to repurpose our RV260w as a wireless access point. I tried already, but I was trying to use the WAN ...
3
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1answer
1k views

How to setup a WAN port in Cisco ISR 1111?

The C1111-8p has 2 WAN ports and 8 switch ports. I am trying to set up the WAN port to an optical fiber modem, the ISP provided: IP address Mask Gateway DNS1 and DN2 I need to set up the port GE 0/0/...
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0answers
270 views

Need to configure site to site SSL VPN between two Cisco routers

I would like to configure site-to-site SSL VPN between two sites. I originally set up an IPSec VPN between the two Cisco routers and found I was only getting 10 percent of the available bandwidth. ...
2
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1answer
1k views

Duplex mismatch between a Fast Ethernet router and Gigabit Ethernet switch with auto negotiation

i am connecting c3745 router on fast ethernet 0/0 interface with a IOSvL2 switch on gigabit ethernet 0/1 on GNS3. i have set the negotiation on the switch to auto for all interfaces on the switch. ...
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5answers
2k views

Why do Vlans need routers to communicate?

Why do devices on two separate VLANs (Virtual LANs) implemented on the same switch require a router to communicate?
4
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1answer
276 views

Cisco 2960L and ISR 4331 throttled WAN speeds

I have tried finding a solution to this issue and the closest I have found thus far can be found here. https://www.reddit.com/r/networking/comments/8f2sn0/throughput_limited_by_cisco_2960_switch/ My ...
2
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1answer
107 views

Need some help booting Cisco 2600 Router

I'm new to the forum and I'm working on my CCNA cert. I received a 2600 Router last week and it boots but only into ROM mode. It appears it needs more memory to run the current image. Besides adding ...
3
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1answer
137 views

Can a router be part of multiple HSRP groups?

Because we configure HSRP on interface level, is that possible?
3
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3answers
921 views

Do VLANs within a subnet need to have their own subnet for router on a stick?

I have been creating a network lab in packet tracer for practice. I have 3 vlans in subnet A and I am trying to configure router on a stick at gig6/0 on the bottom left of the image. Do I need to ...
4
votes
1answer
176 views

Rate Limit on Main Aggregated Interface (AE) without applying on Unit Level in Juniper MX

I want to apply rate limit on Main Aggregated Interface (AE) without applying on unit level. We have a customer connected with our Juniper MX480 via 100G Interface. The single 100G interface is a part ...
1
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1answer
76 views

How to explain that a route has two different AS numbers?

I have a question about the AS path, see the below example where I show the route 114.114.114.114. This shows several BGP routes. See the fist route item. The AS path is 4809 4134 I, I want to know ...
0
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1answer
270 views

Can not use `update-source` in bgp neighbor command in Cisco Packet Tracer

In my Cisco Packet Tracer, I have a ISR4321 router: Router1(config-router)#neighbor 12.0.0.2 update-source lo0 ^ % Invalid input detected at '^' marker. I ...
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1answer
2k views

What's the meaning of `State` and `PfxRcd`?

When I execute the show ip bgp summary, I get the bellow data: Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 12.0.0.2 4 200 199 190 12 0 ...
2
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1answer
319 views

What's the commands of Cisco query bgp neighbor table, bgp table and router table?

In the AS router, I want to query its bgp neighbor table, bgp table, and router table. what's the commands of them?
3
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3answers
471 views

Why the last AS PATH item always is `I` or `?`? [duplicate]

you see my snapshot from m Juniper Router, I want to find the routes of 114.114.114.114, but there always get Idle or a ?, why:
0
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1answer
104 views

Without NAT or NAP, can a host in the Internet send a response back to a host in a private network? [duplicate]

Suppose a router device connect a private network and the Internet, and doesn't have NAT or NAPT features. If some application on a host inside the private network sends some packets to a host in ...
0
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1answer
58 views

Is “gateway” a concept between two or more networks or a concept belonging to just one network?

Is "gateway" a concept between two or more networks or a concept belonging to just one network? When a device is connected to two networks, if it is listed as gateway in the routing tables of the ...
0
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1answer
76 views

My BGP router does not advertise configured prefixes

I have two Routers, which are Router1(BGP 100) and Router2(BGP 200), they have set up BGP neighbor for each other: this is my Router1's BGP configuration: ! router bgp 100 bgp log-neighbor-changes ...
0
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1answer
281 views

Why Cisco BGP neighbor command need the remote-as number?

When I in my Router2 add a neighbor, the bellow is my command: Router2(config-router)#neighbor 12.0.0.1 remote-as 100 you see, I need write two params, one is neighbor address, and the other is its ...
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3answers
218 views

Is a gateway both a router and a NAT?

From Tanenbaum's Computer Networks: The general name for a machine that makes a connection between two or more networks and provides the necessary translation, both in terms of hardware and ...
0
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1answer
37 views

Cisco create BGP connection, do we need two direction's neighbor command?

I have two routers like bellow: in the Router1, I configured like bellow: ! router bgp 100 bgp log-neighbor-changes no synchronization neighbor 12.0.0.2 remote-as 200 network 1.0.0.0 mask 255....
2
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1answer
46 views

one uplink, two routers for redundancy

Let's say i have two linux boxes, RouterA and RouterB, both with two NICs (eth0 and eth1). RouterA/eth0 is connected to an internet uplink. RouterA/eth1 and RouterB/eth1 are directly connected. What ...
3
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3answers
134 views

Why can the BGP protocol be implemented across routers, but the OSPF protocol can only be implemented direct connected routers?

Why can the BGP protocol be implemented across routers? But the OSPF protocol can only be implemented on directly connected routers? Is the OSPF protocol based on IP? we know the BGP is based on ...
2
votes
1answer
100 views

Juniper router how to check the BGP process port?

Juniper router how to check the BGP process port? If I have a router with IP address 12.12.21.1, we know it run a BGP process, which use TCP 179 port as default. How can I check if port 179 is ...
4
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2answers
280 views

How to understand the output below from BGP?

I don't understand some data of the show route: admin@MX-RE0# run show route 36.250.236.6 inet.0: 736608 destinations, 806660 routes (736608 active, 0 holddown, 7 hidden) + = Active Route, - = Last ...
6
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1answer
492 views

Can non-recursive BGP route be used to determine next-hop for recursive BGP route?

In BGP recursive scenario, the recursive route is taking an unexpected next-hop. Here is the routing table: S* 0.0.0.0/0 [10/0] via 10.10.10.1, wan B 172.16.5.0/24 [20/0] via 172.80.80.1, MPLS, ...
0
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2answers
119 views

What are the differences between packet forwarding and network address translation in layer 3?

What are the differences between packet forwarding and network address translation in layer 3? Is packet forwarding done by a router between two networks that use public IP addresses? Is network ...
2
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2answers
312 views

How to: Setting up SNMP on various Cisco platforms & Can you recover or configure a switch using SNMP?

How do you setup SNMP on different Cisco switches or routers? Is it possible to limit the IP addresses/subnets, that can access the SNMP communities via access lists? How do you recover or configure ...
2
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0answers
203 views

How to adjust output queue length on Cisco IOS synchronous PPP (Dialer/Virtual-access) interfaces [duplicate]

I have a Cisco 3845 running IOS 15.3(3)XB12 which is accepting synchronous MLPPP calls from ISDN lines via a PRI. I want to reduce the size of the output queue on the router's PPP interfaces, but the ...
2
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0answers
27 views

How to recover/reset password on Ascend/Lucent SuperPipe 155

I am trying to set up an Ascend/Lucent SuperPipe 155 ISDN router that I don't know the password to. I need to recover or reset this password before I can use the router. I found a reset procedure on a ...
2
votes
1answer
609 views

How to save the initial startup configuration in IOS XR?

I'm willing to try all the Segment Routing implementations one-by-one in XRv 9000 Router. Each time I have a specific implementation for SR e.g., SR-TE, SR-MPLS, SR-OSPF, and SR-ISIS ... etc. The ...
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1answer
62 views

MAc address or IP address? which one gets used from my pc to router? [duplicate]

Question 1) which one is used nowadays? NAT or PAT? Question 2) as I knew, when my pc requests some website, what happens is , the data(packets) from my pc go to router. then router makes the request ...
0
votes
1answer
120 views

Wireshark remote hosts

I configured a rip network. I connected two PCS to router 1, router 1 is connected to router 2 and PC 3 is connected to router 2. When I pinged PC 3 and looked at this in wireshark, in the source it ...
3
votes
1answer
673 views

Can I limit bandwidth for certain IP address, subnet or VLAN on Cisco 881?

I have a router with several workstations running on the switched ports. I need to limit their WAN bandwidth. I tried to use rate-limit on Vlan1, but it looks like it had no effect. What is the ...
0
votes
1answer
286 views

Unable to configure SR-TE (Segment Routing Traffic Engineering) in CSR 1000v

I'm trying to configure SR-TE (Segment Routing Traffic Engineering) in CSR 1000v IOS XE 16 using the official tutorial in here Segment Routing Traffic Engineering (SR-TE) I have the same topology in ...
1
vote
1answer
60 views

What does the 'network w.x.y.z' RIPv2 command specify?

I'm studying networking protocols, and am starting with RIP. When configuring RIPv2, I see 2 pieces of information you need to relay to the router: Which interfaces to advertise RIP updates on Which ...
0
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0answers
85 views

ASA - communication between 2 tunnels

I have two IPSEC tunnels with an ASA in the middle Site A - 10.20.4.0 /24 (65.176.80.84) Site B - 192.168.142.0 /24 ASA - 10.99.206.0 /24 (95.12.22.33 Site A - 10.20.4.0 /24 can reach the ASA and ...
0
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0answers
257 views

How Cisco Line Protocol works

How do Cisco Line Protocol works ? I could read this: https://www.cisco.com/c/en/us/support/docs/content-networking/keepalives/118390-technote-keepalive-00.html, about Ethernet Interfaces keepalive ...
3
votes
1answer
552 views

L3 and L2 interfaces in ACL

What is L3 and L2 interfaces in ACL feature and why ethernet access-lists will not support L3 interfaces
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2answers
79 views

802.1X Auth for Clients and Servers

I'm about to introduce 802.1X Authentication to my current network for wifi and wired connections: My Setup: I have a Windows Domain Controller and I wanted to use the Network Policy Service for ...
6
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3answers
2k views

Can I announce prefix 161.117.25.0/24 even though I don't have all of /24 IPs?

I'm managing one BGP router, under the router I'm trying to announce the following IP prefix:161.117.25.0/24. But the problem is that some of the IP addresses were borrowed by other AS(Autonomous ...

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