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Questions tagged [ppp]

For questions about Point-to-Point Protocol (PPP), a data link protocol typically used in establishing a direct connection between two nodes.

2
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0answers
37 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 ...
0
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1answer
33 views

Assigning static IP addresses to dialin PPP users on Cisco IOS

I have a Cisco router running IOS 15.3 serving as a dial-in PPP endpoint for a handful of modems. I am using local authentication and a local IP pool to hand out dynamic IP addresses to the callers; ...
0
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0answers
54 views

Why does PAP authentication not work in Packet tracer 7.2?

Note : Platform = Packet Tracer 7.2.1 for Linux 64 bit on Fedora 29. I configured two serial interfaces in packet tracer v7.2 for PAP authentication. While one of them has the status up/up, the ...
3
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1answer
47 views

Why are the Address and Control fields constant in PPP protocol?

I saw that address and control fields are constant in PPP protocol. What is the need for even having a field that has constant value in it if we had not have this field then wouldn't it have saved ...
2
votes
1answer
241 views

How exactly does CHAP authentication work?

Let's assume that pppd returns following message: rcvd [CHAP Challenge id=0x1 <12345>, name = ""] and password is "test". What string should I use to calculate MD5 hash for CHAP Response? [...
1
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2answers
386 views

What is a “rotary dialer” in the context of dialup connections?

Some friends and I have discussed setting up a PPP dialup Internet gateway (solely for private use) for fun/nostalgia purposes. I've been reading through the Linux-PPP Howto at TLDP (old, I know, but ...
2
votes
1answer
179 views

How do protocols like PPTP, L2TP work below IP level

I have been using these protocols without deep understand how everything works under the hood. I understand a process of tunneling as follows When we are using protocols like OpenVPN, IPSec, SSH ...
2
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1answer
261 views

PPP CHAP Authentication password requirement

What is the requirement for CHAP authentication on a PPP interface? I thought both routers had to have the same password defined, such as below. r1> username r2 password demo r2> username r1 ...
1
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2answers
304 views

IPv6 in PPP - should be an Interface Identifier negotiated FOR both ends of a link? Clarification of RFC 5072 needed

I am trying to implement IPv6 in an existing VPN PPP software, but having hard time of understanding some of the RFC 5072 sections meaning. Namely, section 4.1. Assumption 1: PPP interfaces do not ...
1
vote
1answer
331 views

Why is L2TP based on PPP and not PPPoE?

I'm trying to grasp why L2TP is based on PPP. I thought PPP was a protocol for point-to-point situations where you don't have Ethernet. So why/how is L2TP using PPP in order to establish communication ...
2
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2answers
2k views

What does State PADISNT mean/stand for? (in CiscoRouter# show pppoe session)

I stumbled upon this while doing Person VUE Test Prep for CCNA and I came up with a question that google wasn't that helpful for. (This is just for curiosity, so a basic answer will do, but for others ...
1
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1answer
572 views

How to decipher, why the pppoe interface has disconnected?

I am using a Ubiquity Edgerouter X, which is connected to a Draytek modem. This is the log from the pppoe interface: #######@ubnt:~$ show interfaces pppoe pppoe0 log Tue Jun 13 06:26:00 IST 2017: PPP ...
1
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2answers
393 views

What is PPPOE line protocol?

In serial wan connection we use PPP or HDLC line protocols,but where would we use PPPOE? What is Ethernet in this term 'PPPOE'?
1
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1answer
56 views

Where the password is stored when using ppp protocol

The question might sound dumb, but you never learn if you do not ask. When using PPP as a datalink layer, it offers you authentication by using username and password. Where is the username and ...
5
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2answers
329 views

How is the length of a PPP frame known?

How does the receiver determine the length of a PPP frame (not PPPoE or PPPoA)? Structure of a PPP frame shows no length field. Sure, at the end of the frame there is a 2-byte checksum followed by a ...
0
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1answer
455 views

IPCP DNS : Configure-Reject [closed]

I'm working with a VxWorks PPP server running on an embedded system. There seems to be a problem with IPCP DNS negotiation. Each time the PPP server offers a IPCP to a client, the client seems to be ...
2
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1answer
1k views

PPP, VPN, Tunneling and OSI model

I am really confused about tunneling protocol family and all related protocols. I read a bunch of articles, rfc but still cannot get the idea. I will put my questions between my explanation. A ...
0
votes
1answer
204 views

PPP sessions on packet return?

Here is a picture of a an xDSL deployment : The BRAS is the termination for PPP sessions. The customer modem establishes a session with the BRAS, gets authenticated and can then access the ISP's ...
1
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3answers
2k views

Configuring PPPoE client through OMCI on Huawei ma5608T

We've received an OLT ma5608T and an ONT hg8245H for a short period of time - we want to see if Huawei is better than Zhone. We don't have a full documentation for this OLT because we're not a partner ...
2
votes
2answers
2k views

Why are /30 subnet used for PPP connections?

Our telephone company has recently set us up a new ADSL connection. It consists of a PPP link over ATM. The connection comes with a public /30 subnet that we can use to our liking. We used one of the ...
1
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1answer
60 views

PPP compression and encryption: which one happens first?

If PPP is enabled for both compression and encryption, which one happens first, compression or encryption, before the PPP sends the data over the physical link?
1
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1answer
255 views

Why PPP cares about network layer?

Why PPP have protocol field? Isn't whole purpose of partitioning communication system to have simple isolated subsystems?
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2answers
760 views

Link layer protocols used by ISP?

Newbie networking question here... Do ISPs generally use the same link layer protocols (Ethernet, ARP to relate to network layer 3, etc.) that are used on LANs? In school I learned in some detail ...
1
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2answers
68 views

Is PPP used to connect immediately adjacent hosts on a network?

I know PPP is used for point-to-point connections. The Wikipedia article for "point-to-point" says that the term is used to refer to a wire that links only two computers or networks, as opposed to, ...
1
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1answer
514 views

What is happening during CHAP PPP authentication between Cisco routers?

I'm going through the great CBT nuggets series for the CCNA. In the video on WAN protocols Jeremy sets up a PPP connection between two routers using CHAP authentication. On each router he adds a ...
1
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1answer
79 views

Can I assign a ppp serial link to a subnetwork that is also being used?

Let's say a network admin is provided a /24 IP address and asked to create a network that involves two different subnetworks that are distant to each other. I have learned that I need to assign a ...
2
votes
2answers
8k views

Why PPTP, L2TP, PPPOE are in OSI Layer2?

PPTP, L2TP, PPPOE - these are tunneling protocols. And they are Data link Layer protocols. Why? As I understood, Layer2 protocols work only in same subnet. They don't use IP addresses and cannot be ...
1
vote
1answer
2k views

How does PPPOE bridging work?

How does the authentication take place in a pppoe bridge setup assuming I have a bridge modem and a router that is capable of maintaining a bridge connection both connected to an un-managed switch? ...
4
votes
1answer
972 views

Will an ERICSSON T720G GPON ONU & a Linux box work as an upstream PPPoE BRAS in our demo setup?

I am a volunteer teacher trying to get my students fired up by learning Broadband. Accordingly I am building a small scale DSL/PPPoE Broadband network that they can touch, deconstruct and put back ...
1
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2answers
337 views

Line Sync when there is supposed to be no ADSL codes on the line? [closed]

I have a client who had ADSL (1500/256), and in an attempt to get her a faster connection, she tried to churn to a different provider. Long story short, the other provider will not supply adsl ...
9
votes
1answer
4k views

PPPoA ADSL Configuration with external modem on Cisco 891

Context We use Cisco 891 routers as CPE for several client sites. They are all running IOS 15. Cisco IOS Software, C890 Software (C890-UNIVERSALK9-M), Version 15.0(1)M8, RELEASE SOFTWARE (fc1) The ...
11
votes
3answers
2k views

Please help me understand this ADSL configuration

I've been working across many sites around the world with ADSL. The first output below is the one I've used many many times & I'm therefore most familiar with. It's from a site in the UK. ...
13
votes
2answers
3k views

How is the payload distributed across Multilink PPP connections

A site I support uses 3 T1s setup with multilink PPP. They are trying to use Jive which is a hosted VoIP provider, with horrible results. I want to know how packets are distributed between the ...