Re: /31 subnet. [7:27742]
Point to point connections, with a /30 you waste 50% of the avaivalable addresses. Dave Nicolas FEVRIER wrote: > > Hi group, > > I'm puzzled by the use of /31 subnets... > Anybody can explain me the benefits of such a subnet on an interface ? > > Thanxx. > > Nicolas. -- David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 "Emotion should reflect reason not guide it" Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27745&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
Sincerely do not know, when you find out let me know. To me using /31 is against all subnet rules, /31 gives you a subnet mask of 255.255.255.254, with two host addresses each, but these addresses are not usable. The most I have used and seen people use is /30 (255.255.255.252), for WAN interface IP address allocations. Regards. Oletu - Original Message - From: Nicolas FEVRIER To: Sent: Thursday, November 29, 2001 2:39 PM Subject: /31 subnet. [7:27742] > Hi group, > > I'm puzzled by the use of /31 subnets... > Anybody can explain me the benefits of such a subnet on an interface ? > > Thanxx. > > Nicolas. _ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27783&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
Maybe I'm missing something, but there are only 2 useable addresses in a /30, and only 2 interfaces participating in a point-to-point link, so how are there 50% of the addresses wasted. Steve ""MADMAN"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Point to point connections, with a /30 you waste 50% of the > avaivalable addresses. > > Dave > > Nicolas FEVRIER wrote: > > > > Hi group, > > > > I'm puzzled by the use of /31 subnets... > > Anybody can explain me the benefits of such a subnet on an interface ? > > > > Thanxx. > > > > Nicolas. > -- > David Madland > Sr. Network Engineer > CCIE# 2016 > Qwest Communications Int. Inc. > [EMAIL PROTECTED] > 612-664-3367 > > "Emotion should reflect reason not guide it" Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27795&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: /31 subnet. [7:27742]
I think this can sum it up. http://www.faqs.org/rfcs/rfc3021.html -Eric -Original Message- From: VoIP Guy [mailto:[EMAIL PROTECTED]] Sent: Friday, November 30, 2001 7:33 AM To: [EMAIL PROTECTED] Subject: Re: /31 subnet. [7:27742] Maybe I'm missing something, but there are only 2 useable addresses in a /30, and only 2 interfaces participating in a point-to-point link, so how are there 50% of the addresses wasted. Steve ""MADMAN"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Point to point connections, with a /30 you waste 50% of the > avaivalable addresses. > > Dave > > Nicolas FEVRIER wrote: > > > > Hi group, > > > > I'm puzzled by the use of /31 subnets... > > Anybody can explain me the benefits of such a subnet on an interface ? > > > > Thanxx. > > > > Nicolas. > -- > David Madland > Sr. Network Engineer > CCIE# 2016 > Qwest Communications Int. Inc. > [EMAIL PROTECTED] > 612-664-3367 > > "Emotion should reflect reason not guide it" Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27809&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
Law of subnets is a tradeoff. Bigger subnets, have higher efficiency, at the cost of bigger broadcast domains. Smaller subnets have abysmal efficiency, at the benefit of smaller broadcast domains. /31 is a new RFC proposed rule which eliminates the loss of effiency of 50% to.. 0%. /30 has 2 usable addresses but loses 2 for broadcast and network. So, you need 4 ips to make the subnet, but you only can use 2. 50% efficiency. /31 is going to let you take 2, and use 2, and ignore the broadcast and network need. This is ideal for point to point. At 08:32 AM 11/30/01 -0500, VoIP Guy wrote: >Maybe I'm missing something, but there are only 2 useable addresses in a >/30, and only 2 interfaces participating in a point-to-point link, so how >are there 50% of the addresses wasted. > >Steve > > >""MADMAN"" wrote in message >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Point to point connections, with a /30 you waste 50% of the > > avaivalable addresses. > > > > Dave > > > > Nicolas FEVRIER wrote: > > > > > > Hi group, > > > > > > I'm puzzled by the use of /31 subnets... > > > Anybody can explain me the benefits of such a subnet on an interface ? > > > > > > Thanxx. > > > > > > Nicolas. > > -- > > David Madland > > Sr. Network Engineer > > CCIE# 2016 > > Qwest Communications Int. Inc. > > [EMAIL PROTECTED] > > 612-664-3367 > > > > "Emotion should reflect reason not guide it" -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27810&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
It doesn't work in Cisco routers. ""Carroll Kong"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Law of subnets is a tradeoff. Bigger subnets, have higher > efficiency, at the cost of bigger broadcast domains. Smaller subnets have > abysmal efficiency, at the benefit of smaller broadcast domains. > /31 is a new RFC proposed rule which eliminates the loss of > effiency of 50% to.. 0%. > /30 has 2 usable addresses but loses 2 for broadcast and > network. So, you need 4 ips to make the subnet, but you only can use > 2. 50% efficiency. /31 is going to let you take 2, and use 2, and ignore > the broadcast and network need. This is ideal for point to point. > > At 08:32 AM 11/30/01 -0500, VoIP Guy wrote: > >Maybe I'm missing something, but there are only 2 useable addresses in a > >/30, and only 2 interfaces participating in a point-to-point link, so how > >are there 50% of the addresses wasted. > > > >Steve > > > > > >""MADMAN"" wrote in message > >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > Point to point connections, with a /30 you waste 50% of the > > > avaivalable addresses. > > > > > > Dave > > > > > > Nicolas FEVRIER wrote: > > > > > > > > Hi group, > > > > > > > > I'm puzzled by the use of /31 subnets... > > > > Anybody can explain me the benefits of such a subnet on an interface ? > > > > > > > > Thanxx. > > > > > > > > Nicolas. > > > -- > > > David Madland > > > Sr. Network Engineer > > > CCIE# 2016 > > > Qwest Communications Int. Inc. > > > [EMAIL PROTECTED] > > > 612-664-3367 > > > > > > "Emotion should reflect reason not guide it" > -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27811&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
Actually, it does work with the correct platform and IOS version. Here's the link. http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t2/ft31addr.htm Craig At 09:44 AM 11/30/2001 -0500, you wrote: >It doesn't work in Cisco routers. > >""Carroll Kong"" wrote in message >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Law of subnets is a tradeoff. Bigger subnets, have higher > > efficiency, at the cost of bigger broadcast domains. Smaller subnets have > > abysmal efficiency, at the benefit of smaller broadcast domains. > > /31 is a new RFC proposed rule which eliminates the loss of > > effiency of 50% to.. 0%. > > /30 has 2 usable addresses but loses 2 for broadcast and > > network. So, you need 4 ips to make the subnet, but you only can use > > 2. 50% efficiency. /31 is going to let you take 2, and use 2, and ignore > > the broadcast and network need. This is ideal for point to point. > > > > At 08:32 AM 11/30/01 -0500, VoIP Guy wrote: > > >Maybe I'm missing something, but there are only 2 useable addresses in a > > >/30, and only 2 interfaces participating in a point-to-point link, so how > > >are there 50% of the addresses wasted. > > > > > >Steve > > > > > > > > >""MADMAN"" wrote in message > > >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > > Point to point connections, with a /30 you waste 50% of the > > > > avaivalable addresses. > > > > > > > > Dave > > > > > > > > Nicolas FEVRIER wrote: > > > > > > > > > > Hi group, > > > > > > > > > > I'm puzzled by the use of /31 subnets... > > > > > Anybody can explain me the benefits of such a subnet on an interface >? > > > > > > > > > > Thanxx. > > > > > > > > > > Nicolas. > > > > -- > > > > David Madland > > > > Sr. Network Engineer > > > > CCIE# 2016 > > > > Qwest Communications Int. Inc. > > > > [EMAIL PROTECTED] > > > > 612-664-3367 > > > > > > > > "Emotion should reflect reason not guide it" > > -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27816&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
It does work with Cisco routers, but it's a new feature in 12.2. Hmm...it may even be 12.2T, not 12.2, but it is definitely available now. >>> "VoIP Guy" 11/30/01 7:44:28 AM >>> It doesn't work in Cisco routers. ""Carroll Kong"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Law of subnets is a tradeoff. Bigger subnets, have higher > efficiency, at the cost of bigger broadcast domains. Smaller subnets have > abysmal efficiency, at the benefit of smaller broadcast domains. > /31 is a new RFC proposed rule which eliminates the loss of > effiency of 50% to.. 0%. > /30 has 2 usable addresses but loses 2 for broadcast and > network. So, you need 4 ips to make the subnet, but you only can use > 2. 50% efficiency. /31 is going to let you take 2, and use 2, and ignore > the broadcast and network need. This is ideal for point to point. > > At 08:32 AM 11/30/01 -0500, VoIP Guy wrote: > >Maybe I'm missing something, but there are only 2 useable addresses in a > >/30, and only 2 interfaces participating in a point-to-point link, so how > >are there 50% of the addresses wasted. > > > >Steve > > > > > >""MADMAN"" wrote in message > >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > Point to point connections, with a /30 you waste 50% of the > > > avaivalable addresses. > > > > > > Dave > > > > > > Nicolas FEVRIER wrote: > > > > > > > > Hi group, > > > > > > > > I'm puzzled by the use of /31 subnets... > > > > Anybody can explain me the benefits of such a subnet on an interface ? > > > > > > > > Thanxx. > > > > > > > > Nicolas. > > > -- > > > David Madland > > > Sr. Network Engineer > > > CCIE# 2016 > > > Qwest Communications Int. Inc. > > > [EMAIL PROTECTED] > > > 612-664-3367 > > > > > > "Emotion should reflect reason not guide it" > -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27817&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: /31 subnet. [7:27742]
Sorry. Looks like 12.2(2)T. http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122 t/122t2/ft31addr.htm#xtocid104191 -Eric -Original Message- From: VoIP Guy [mailto:[EMAIL PROTECTED]] Sent: Friday, November 30, 2001 8:44 AM To: [EMAIL PROTECTED] Subject: Re: /31 subnet. [7:27742] It doesn't work in Cisco routers. ""Carroll Kong"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Law of subnets is a tradeoff. Bigger subnets, have higher > efficiency, at the cost of bigger broadcast domains. Smaller subnets have > abysmal efficiency, at the benefit of smaller broadcast domains. > /31 is a new RFC proposed rule which eliminates the loss of > effiency of 50% to.. 0%. > /30 has 2 usable addresses but loses 2 for broadcast and > network. So, you need 4 ips to make the subnet, but you only can use > 2. 50% efficiency. /31 is going to let you take 2, and use 2, and ignore > the broadcast and network need. This is ideal for point to point. > > At 08:32 AM 11/30/01 -0500, VoIP Guy wrote: > >Maybe I'm missing something, but there are only 2 useable addresses in a > >/30, and only 2 interfaces participating in a point-to-point link, so how > >are there 50% of the addresses wasted. > > > >Steve > > > > > >""MADMAN"" wrote in message > >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > Point to point connections, with a /30 you waste 50% of the > > > avaivalable addresses. > > > > > > Dave > > > > > > Nicolas FEVRIER wrote: > > > > > > > > Hi group, > > > > > > > > I'm puzzled by the use of /31 subnets... > > > > Anybody can explain me the benefits of such a subnet on an interface ? > > > > > > > > Thanxx. > > > > > > > > Nicolas. > > > -- > > > David Madland > > > Sr. Network Engineer > > > CCIE# 2016 > > > Qwest Communications Int. Inc. > > > [EMAIL PROTECTED] > > > 612-664-3367 > > > > > > "Emotion should reflect reason not guide it" > -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27820&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
En riponse ` VoIP Guy : > It doesn't work in Cisco routers. Actually, Cisco supports this 3021... http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/12 2t2/ft31addr.htm My apologies, I didn't know this url before posting... Nicolas. > > ""Carroll Kong"" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Law of subnets is a tradeoff. Bigger subnets, have higher > > efficiency, at the cost of bigger broadcast domains. Smaller subnets > have > > abysmal efficiency, at the benefit of smaller broadcast domains. > > /31 is a new RFC proposed rule which eliminates the loss of > > effiency of 50% to.. 0%. > > /30 has 2 usable addresses but loses 2 for broadcast and > > network. So, you need 4 ips to make the subnet, but you only can > use > > 2. 50% efficiency. /31 is going to let you take 2, and use 2, and > ignore > > the broadcast and network need. This is ideal for point to point. > > > > At 08:32 AM 11/30/01 -0500, VoIP Guy wrote: > > >Maybe I'm missing something, but there are only 2 useable addresses > in a > > >/30, and only 2 interfaces participating in a point-to-point link, so > how > > >are there 50% of the addresses wasted. > > > > > >Steve > > > > > > > > >""MADMAN"" wrote in message > > >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > > Point to point connections, with a /30 you waste 50% of the > > > > avaivalable addresses. > > > > > > > > Dave > > > > > > > > Nicolas FEVRIER wrote: > > > > > > > > > > Hi group, > > > > > > > > > > I'm puzzled by the use of /31 subnets... > > > > > Anybody can explain me the benefits of such a subnet on an > interface > ? > > > > > > > > > > Thanxx. > > > > > > > > > > Nicolas. > > > > -- > > > > David Madland > > > > Sr. Network Engineer > > > > CCIE# 2016 > > > > Qwest Communications Int. Inc. > > > > [EMAIL PROTECTED] > > > > 612-664-3367 > > > > > > > > "Emotion should reflect reason not guide it" > > -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27821&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
>Maybe I'm missing something, but there are only 2 useable addresses in a >/30, and only 2 interfaces participating in a point-to-point link, so how >are there 50% of the addresses wasted. > >Steve But there are 4 actual addresses in a /30. Two are not usable. All the addresses in a /31 are both actual and usable. > >""MADMAN"" wrote in message >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... >> Point to point connections, with a /30 you waste 50% of the >> avaivalable addresses. >> >>Dave >> >> Nicolas FEVRIER wrote: >> > >> > Hi group, >> > >> > I'm puzzled by the use of /31 subnets... >> > Anybody can explain me the benefits of such a subnet on an interface ? >> > >> > Thanxx. >> > >> > Nicolas. >> -- >> David Madland >> Sr. Network Engineer >> CCIE# 2016 >> Qwest Communications Int. Inc. >> [EMAIL PROTECTED] >> 612-664-3367 >> >> "Emotion should reflect reason not guide it" Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27824&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
>It doesn't work in Cisco routers. Only in quite recent releases, and I can't tell you numbers offhand. Might need to be an ISP release train. > >""Carroll Kong"" wrote in message >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... >> Law of subnets is a tradeoff. Bigger subnets, have higher >> efficiency, at the cost of bigger broadcast domains. Smaller subnets have >> abysmal efficiency, at the benefit of smaller broadcast domains. >> /31 is a new RFC proposed rule which eliminates the loss of >> effiency of 50% to.. 0%. >> /30 has 2 usable addresses but loses 2 for broadcast and >> network. So, you need 4 ips to make the subnet, but you only can use >> 2. 50% efficiency. /31 is going to let you take 2, and use 2, and ignore >> the broadcast and network need. This is ideal for point to point. >> >> At 08:32 AM 11/30/01 -0500, VoIP Guy wrote: >> >Maybe I'm missing something, but there are only 2 useable addresses in a >> >/30, and only 2 interfaces participating in a point-to-point link, so how >> >are there 50% of the addresses wasted. >> > >> >Steve >> > >> > >> >""MADMAN"" wrote in message >> >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... >> > > Point to point connections, with a /30 you waste 50% of the >> > > avaivalable addresses. >> > > >> > > Dave >> > > >> > > Nicolas FEVRIER wrote: >> > > > >> > > > Hi group, >> > > > >> > > > I'm puzzled by the use of /31 subnets... >> > > > Anybody can explain me the benefits of such a subnet on an interface >? >> > > > >> > > > Thanxx. >> > > > >> > > > Nicolas. >> > > -- >> > > David Madland >> > > Sr. Network Engineer >> > > CCIE# 2016 >> > > Qwest Communications Int. Inc. >> > > [EMAIL PROTECTED] >> > > 612-664-3367 >> > > >> > > "Emotion should reflect reason not guide it" >> -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27826&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
Network and broadcast address not needed on p-to-p links. - Original Message - From: "VoIP Guy" To: Sent: Friday, November 30, 2001 5:32 AM Subject: Re: /31 subnet. [7:27742] > Maybe I'm missing something, but there are only 2 useable addresses in a > /30, and only 2 interfaces participating in a point-to-point link, so how > are there 50% of the addresses wasted. > > Steve > > > ""MADMAN"" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Point to point connections, with a /30 you waste 50% of the > > avaivalable addresses. > > > > Dave > > > > Nicolas FEVRIER wrote: > > > > > > Hi group, > > > > > > I'm puzzled by the use of /31 subnets... > > > Anybody can explain me the benefits of such a subnet on an interface ? > > > > > > Thanxx. > > > > > > Nicolas. > > -- > > David Madland > > Sr. Network Engineer > > CCIE# 2016 > > Qwest Communications Int. Inc. > > [EMAIL PROTECTED] > > 612-664-3367 > > > > "Emotion should reflect reason not guide it" Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27813&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: /31 subnet. [7:27742]
Sure, but then what are your network and broadcast addresses? ccie1ab -Original Message- From: MADMAN [mailto:[EMAIL PROTECTED]] Sent: Thursday, November 29, 2001 6:22 PM To: [EMAIL PROTECTED] Subject: Re: /31 subnet. [7:27742] Point to point connections, with a /30 you waste 50% of the avaivalable addresses. Dave Nicolas FEVRIER wrote: > > Hi group, > > I'm puzzled by the use of /31 subnets... > Anybody can explain me the benefits of such a subnet on an interface ? > > Thanxx. > > Nicolas. -- David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 "Emotion should reflect reason not guide it" Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27838&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
I participated in the Cisco LAN Technologies seminar and the Cisco guy said it was recently added in their support. I have been searching around and so far have not found anything. Debbie Westall --- VoIP Guy wrote: > It doesn't work in Cisco routers. > > ""Carroll Kong"" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Law of subnets is a tradeoff. Bigger subnets, > have higher > > efficiency, at the cost of bigger broadcast > domains. Smaller subnets have > > abysmal efficiency, at the benefit of smaller > broadcast domains. > > /31 is a new RFC proposed rule which > eliminates the loss of > > effiency of 50% to.. 0%. > > /30 has 2 usable addresses but loses 2 > for broadcast and > > network. So, you need 4 ips to make the subnet, > but you only can use > > 2. 50% efficiency. /31 is going to let you take > 2, and use 2, and ignore > > the broadcast and network need. This is ideal for > point to point. > > > > At 08:32 AM 11/30/01 -0500, VoIP Guy wrote: > > >Maybe I'm missing something, but there are only 2 > useable addresses in a > > >/30, and only 2 interfaces participating in a > point-to-point link, so how > > >are there 50% of the addresses wasted. > > > > > >Steve > > > > > > > > >""MADMAN"" wrote in message > > >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > > Point to point connections, with a /30 you > waste 50% of the > > > > avaivalable addresses. > > > > > > > > Dave > > > > > > > > Nicolas FEVRIER wrote: > > > > > > > > > > Hi group, > > > > > > > > > > I'm puzzled by the use of /31 subnets... > > > > > Anybody can explain me the benefits of such > a subnet on an interface > ? > > > > > > > > > > Thanxx. > > > > > > > > > > Nicolas. > > > > -- > > > > David Madland > > > > Sr. Network Engineer > > > > CCIE# 2016 > > > > Qwest Communications Int. Inc. > > > > [EMAIL PROTECTED] > > > > 612-664-3367 > > > > > > > > "Emotion should reflect reason not guide it" > > -Carroll Kong [EMAIL PROTECTED] __ Do You Yahoo!? Yahoo! GeoCities - quick and easy web site hosting, just $8.95/month. http://geocities.yahoo.com/ps/info1 Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27839&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
You gotta have the right code. - Original Message - From: "VoIP Guy" To: Sent: Friday, November 30, 2001 6:44 AM Subject: Re: /31 subnet. [7:27742] > It doesn't work in Cisco routers. > > ""Carroll Kong"" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Law of subnets is a tradeoff. Bigger subnets, have higher > > efficiency, at the cost of bigger broadcast domains. Smaller subnets have > > abysmal efficiency, at the benefit of smaller broadcast domains. > > /31 is a new RFC proposed rule which eliminates the loss of > > effiency of 50% to.. 0%. > > /30 has 2 usable addresses but loses 2 for broadcast and > > network. So, you need 4 ips to make the subnet, but you only can use > > 2. 50% efficiency. /31 is going to let you take 2, and use 2, and ignore > > the broadcast and network need. This is ideal for point to point. > > > > At 08:32 AM 11/30/01 -0500, VoIP Guy wrote: > > >Maybe I'm missing something, but there are only 2 useable addresses in a > > >/30, and only 2 interfaces participating in a point-to-point link, so how > > >are there 50% of the addresses wasted. > > > > > >Steve > > > > > > > > >""MADMAN"" wrote in message > > >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > > Point to point connections, with a /30 you waste 50% of the > > > > avaivalable addresses. > > > > > > > > Dave > > > > > > > > Nicolas FEVRIER wrote: > > > > > > > > > > Hi group, > > > > > > > > > > I'm puzzled by the use of /31 subnets... > > > > > Anybody can explain me the benefits of such a subnet on an interface > ? > > > > > > > > > > Thanxx. > > > > > > > > > > Nicolas. > > > > -- > > > > David Madland > > > > Sr. Network Engineer > > > > CCIE# 2016 > > > > Qwest Communications Int. Inc. > > > > [EMAIL PROTECTED] > > > > 612-664-3367 > > > > > > > > "Emotion should reflect reason not guide it" > > -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27831&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
Yes, but why are all zeros and all ones in the host field disallowed? Because they seem to be broadcasts or refer to the entire subnet. On a point-to-point WAN, so what if you send to broadcast? There's only one station on the other end anyway! So IF devices support /31, you can use it. The only advantage would be it wastes fewer addresses, though. Priscilla At 04:03 AM 11/30/01, [EMAIL PROTECTED] wrote: >Sincerely do not know, when you find out let me know. To me using /31 is >against all subnet rules, /31 gives you a subnet mask of 255.255.255.254, >with two host addresses each, but these addresses are not usable. > >The most I have used and seen people use is /30 (255.255.255.252), for WAN >interface IP address allocations. > >Regards. >Oletu > >- Original Message - >From: Nicolas FEVRIER >To: >Sent: Thursday, November 29, 2001 2:39 PM >Subject: /31 subnet. [7:27742] > > > > Hi group, > > > > I'm puzzled by the use of /31 subnets... > > Anybody can explain me the benefits of such a subnet on an interface ? > > > > Thanxx. > > > > Nicolas. >_ >Do You Yahoo!? >Get your free @yahoo.com address at http://mail.yahoo.com Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27856&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: /31 subnet. [7:27742]
Chuck what is the benefit of a broadcast on a p-to-p link. all stations are gonna answer anyway. i.e. the station on the other side of the p-to-p link. - Original Message - From: "Mcfadden, Chuck" To: Sent: Friday, November 30, 2001 8:44 AM Subject: RE: /31 subnet. [7:27742] > Sure, but then what are your network and broadcast addresses? > ccie1ab > > -Original Message- > From: MADMAN [mailto:[EMAIL PROTECTED]] > Sent: Thursday, November 29, 2001 6:22 PM > To: [EMAIL PROTECTED] > Subject: Re: /31 subnet. [7:27742] > > > Point to point connections, with a /30 you waste 50% of the > avaivalable addresses. > > Dave > > Nicolas FEVRIER wrote: > > > > Hi group, > > > > I'm puzzled by the use of /31 subnets... > > Anybody can explain me the benefits of such a subnet on an interface ? > > > > Thanxx. > > > > Nicolas. > -- > David Madland > Sr. Network Engineer > CCIE# 2016 > Qwest Communications Int. Inc. > [EMAIL PROTECTED] > 612-664-3367 > > "Emotion should reflect reason not guide it" Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27852&t=27742 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
