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.

4
votes
1answer
49 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
vote
1answer
70 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
votes
1answer
54 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 ...
0
votes
1answer
94 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
votes
1answer
290 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
votes
3answers
294 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
votes
0answers
30 views

Why does my 1921 Router not bring up its interfaces?

I have the 'no shut' command entered on both interfaces. They work when I enter the command. I copy run start 'wr' Power was cycled for the Router, Switch (3560x-24), Cable modem and AP. They were ...
0
votes
1answer
22 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
votes
1answer
43 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
votes
1answer
47 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
votes
1answer
55 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 ...
1
vote
3answers
42 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
votes
1answer
35 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
votes
1answer
37 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
votes
3answers
96 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
31 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 ...
3
votes
2answers
195 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
votes
1answer
283 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
votes
0answers
18 views

Confuse about type of handover in Mesh Router?

I have difficulty in understand the concept of handover which can be categorized into two: Horizontal or Homogeneous handover Vertical or Heterogeneous handover Horizontal handover occur within the ...
0
votes
1answer
37 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
votes
2answers
69 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 ...
0
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0answers
34 views

MPLS LSPs Unequal Cost Load Balancing in Juniper MX

I have confusion with regard to Juniper MPLS LSP unequal cost balancing. In Juniper we can define 2 or more LSPs between R1 and R2. With some LSPs taking the IGP best path (default behavior) while ...
2
votes
0answers
41 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 ...
1
vote
0answers
18 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
228 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 ...
-1
votes
1answer
39 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
55 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
48 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
81 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
35 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
votes
0answers
54 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
votes
0answers
123 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
55 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
1
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2answers
66 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 ...
0
votes
0answers
39 views

Basic connectivity won't work in Packet Tracer

I've been redoing this multiple times and I'm sure i configured it correctly, however there is nothing happening at all. It's just a basic network with 3 routers and OSPF configured. Here are the ...
6
votes
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 ...
0
votes
1answer
35 views

How does packet traversal works over a public network with NAT overloading

Let's say I have a private network connected to the internet with default gateway 192.168.1.1 on Router1. Now a host(Host#1, 192.168.1.10) on this network wants to send a packet over the public ...
2
votes
0answers
59 views

Is this a valid OSPF topology?

In the following topology: every Backbone router is an ABR. Router 2 belongs to three different areas, area 0, area 1, and area 4. is this a valid topology for OSPF ? it works as expected and it ...
4
votes
1answer
33 views

Is there any problem with using wifi to continuously signal numerous sensors?

The company I work for is developing a sensor network that will require roughly 1 sensor per every 6 m2 or about 160 sensors for a 10,000 sq ft building. They need to synchronize them by sending a ...
1
vote
0answers
74 views

Why do the tunnel protocol on these two router show different values

Two routers R1 and R2 have a tunnel built between them in the 103.103.103.0/24 network. The end point of the tunnel are 75.75.75.2(on R1) and 76.76.76.2(on R2). Can anyone explain why does the Tunnel ...
2
votes
2answers
61 views

In OSPF does a DR consume more resources than a BDR?

What is the best practice in conserving router resources? Should a single ABR router be the DR for all areas? Will that have a negative impact on the resources, or would it be better to let other ...
1
vote
1answer
28 views

Can a VPN tunnel between routers be built with different tunnel protocol on both ends?

I have two routers and the tunnel between them is up and working well. Router1 has GRE/IP as the protocol on its tunnel interface, and as for Router2 the tunnel interface is working with IPSEC/IP. Can ...
2
votes
2answers
96 views

How does a router know the destination mac?

so if I send a packet from a host to another from the same network we know the mac address of both the source and destination. However if the receiver is in a remote network the destination mac ...
1
vote
0answers
84 views

Cisco ISR Zone Based Firewall dual stack not matching returning traffic for ipv6

I have a bit of a problem with my Cisco 1921 ISR config. I have ipv4 (obviously) and also native ipv6 connectivity in my home lab. I am trying to set up the zone based firewall. With ipv4 traffic, the ...
1
vote
1answer
128 views

Difference between PEM 'Not OK' and PEM 'Input Failure' in Juniper

I have one query with regard to PEM (Power Entity Modules) in Juniper routers. On MX series routers, 4 x PEM Modules are installed. However in case 1 x PEM is not receiving power (like Input Power ...
1
vote
2answers
62 views

Which parts cost most of CPU and Memory resources in Router or Switch

I'm a new guy of enterprise network traffic optimization. I'm very curious why the enterprise Router or Switch so expensive. As in my mind the Router just look up route table (I guess it should be a ...
2
votes
3answers
475 views

Does a router send frames or packets?

Perhaps it's a novice question, but does a router send/receive frames? When I read about this subject, it seems that routers decapsulate the frame on arrival, and encapsulate the packet in a frame in ...
3
votes
2answers
61 views

Why isn't web traffic blocked by router?

(A naive/stupid question which I couldn't find answer to on the web.) Why is the internet traffic reaching me even if I haven't set up port forwarding. (For example, I can view websites). What I ...
2
votes
1answer
39 views

One Fiber Optic Line 24 Cores for Multiple Services Transmission

Hello we have a construction project for building a compound of 50+ villas. The aim is build and connect the villas all together transmitting all services through the fiber optic. The services ...
1
vote
2answers
90 views

What's the role of Default Gateway?

It acts as the "gateway" to the Internet,but also from what i have read,it's the last thing a packet would be sent to while trying to route (when checking the senders' route table). Maybe it's the ...