RE: CCDA summerization question
This is possibly one of those situations with just a poorly worded question. Now, to nit-pick at the wording.. "The following IP *ADDRESSES*" -- Addresses, not networks, but ADDRESSES.. Now, is this VLSM summarization, in which case "no bits in the 3rd octet" without doing 2 summaries (50% savings on the routing table traffic, but why when you could 172.16/16 for 75% savings). The other possibility, is (I do this occassionally on firewall rules setups) summarizing for an access list. In other words, "What is an IP/mask combination that will match those 4 addresses." The answer would be : 172.16.0.0 = 172.16..0 172.16.64.0 = 172.16.0100.0 172.16.128.0 = 172.16.1000.0 172.16.192.0 = 172.16.1100.0 Remember that the mask in an access-list etc, does NOT need to be contiguous bits.. therefor : 172.16.0.0 0.0.192.255 (172.16.xx00.x) works fine for those specific addresses (and added feature, doesn't include anything else). Just another point of view to look at this question from. Remember that while writing a Cisco exam, or out in the real world, ASSUME NOTHING. If it does not mention VLSM, don't assume they are talking about VLSM. If possible, check on what the exam says is the "correct" answer, and try to reverse-engineer their thinking to see what topic they are covering. Also, check the erratta for the exam to make sure you are looking at a "correct" answer. Regards, Trevor Corness, CCNA MCSE MCP+I Network Systems Engineer, DataCom BMS Communications Ltd. http://www.bmscom.com "John lay" [EMAIL PROTECTED] wrote in message Guys, While studying for the CCDA, I found the following question in one of the exam preparation sites. The following IP addresses can be summaried by which bit of the 3rd octet 172.16.0.0, 172.16.64.0, 172.16.128.0, 172.16.192.0 --- 1st bit, first 2 bit, first 4 bit, last 6 bit I don't think that the following addresses could be summarized on any bit of the 3rd octet. If you have a look to the 3rd octet 172.16.0.0 --- 172.16..0 172.16.64.0 --- 172.16.0100.0 172.16.128.0--- 172.16.1000.0 172.16.192.0--- 172.16.1100.0 Could someone verify this with me guys ? Thanks a lot BEGIN:VCARD VERSION:2.1 N:Corness;Trevor FN:Trevor Corness ORG:BMS Communications;DataCom TITLE:Network Systems Engineer TEL;PAGER;VOICE:604-631-7867 ADR;WORK:;;2880 Production Way;Burnaby;BC;V5A4T6;Canada LABEL;WORK;ENCODING=QUOTED-PRINTABLE:2880 Production Way=0D=0ABurnaby, BC V5A4T6=0D=0ACanada URL: URL:http://www.bmscom.com EMAIL;PREF;INTERNET:[EMAIL PROTECTED] REV:2921T155409Z END:VCARD
RE: CCDA summerization question
Title: RE: CCDA summerization question I'd have to agree with you. The best summarization possible is 172.16.0.0. -Original Message- From: John lay [mailto:[EMAIL PROTECTED]] Sent: Wednesday, September 27, 2000 12:24 AM To: [EMAIL PROTECTED] Subject: CCDA summerization question Guys, While studying for the CCDA, I found the following question in one of the exam preparation sites. The following IP addresses can be summaried by which bit of the 3rd octet 172.16.0.0, 172.16.64.0, 172.16.128.0, 172.16.192.0 --- 1st bit, first 2 bit, first 4 bit, last 6 bit I don't think that the following addresses could be summarized on any bit of the 3rd octet. If you have a look to the 3rd octet 172.16.0.0 --- 172.16..0 172.16.64.0 --- 172.16.0100.0 172.16.128.0--- 172.16.1000.0 172.16.192.0--- 172.16.1100.0 Could someone verify this with me guys ? Thanks a lot ___ Say Bye to Slow Internet! http://www.home.com/xinbox/signup.html **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: CCDA summerization question
It would be the first 2 bits in the 3rd octet. Go back to subnetting these are network numbers with the netmask of 255.255.192.0 First 2 bits make 192. 256-192 = 64. 64, 128, 192 Scott P. "John lay" [EMAIL PROTECTED] wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... Guys, While studying for the CCDA, I found the following question in one of the exam preparation sites. The following IP addresses can be summaried by which bit of the 3rd octet 172.16.0.0, 172.16.64.0, 172.16.128.0, 172.16.192.0 --- 1st bit, first 2 bit, first 4 bit, last 6 bit I don't think that the following addresses could be summarized on any bit of the 3rd octet. If you have a look to the 3rd octet 172.16.0.0 --- 172.16..0 172.16.64.0 --- 172.16.0100.0 172.16.128.0--- 172.16.1000.0 172.16.192.0--- 172.16.1100.0 Could someone verify this with me guys ? Thanks a lot ___ Say Bye to Slow Internet! http://www.home.com/xinbox/signup.html **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Fwd: Re: CCDA summerization question
You can summarize on the first bit but you would need two summary address statements to cover all 4 networks: 172.16.0.0 mask 255.255.128.0 for the networks 172.16.0.0 and 172.16.64.0 172.16.128.0 mask 255.255.128.0 for the network 172.16.128.0 and 172.16.192.0 Regards, No Shut It would be the first 2 bits in the 3rd octet. Go back to subnetting these are network numbers with the netmask of 255.255.192.0 First 2 bits make 192. 256-192 = 64. 64, 128, 192 Scott P. John lay [EMAIL PROTECTED] wrote in message [EMAIL PROTECTED]" eudora="autourl">news:[EMAIL PROTECTED]... Guys, While studying for the CCDA, I found the following question in one of the exam preparation sites. The following IP addresses can be summaried by which bit of the 3rd octet 172.16.0.0, 172.16.64.0, 172.16.128.0, 172.16.192.0 --- 1st bit, first 2 bit, first 4 bit, last 6 bit I don't think that the following addresses could be summarized on any bit of the 3rd octet. If you have a look to the 3rd octet 172.16.0.0 --- 172.16..0 172.16.64.0 --- 172.16.0100.0 172.16.128.0--- 172.16.1000.0 172.16.192.0--- 172.16.1100.0 Could someone verify this with me guys ? Thanks a lot ___ Say Bye to Slow Internet! http://www.home.com/xinbox/signup.html **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Fwd: Re: CCDA summerization question
All, IP address 172.16.0.0 with a subnet mask of 255.255.192.0 will summarise: 172.16.0.0 172.16.64.0 172.16.128.0 172.16.192.0 So therefore, the answer is the first two bits in third octet of the subnet mask will summarise the above subnets. or more succintly: IP Class: BIP Address: 172.16.0.0 Mask1 Bits: 0Subnet Mask1:255.255.0.0 Mask2 Bits: 0Subnet Mask2:255.255.0.0 Mask3 Bits: 2Subnet Mask3:255.255.192.0 Subnets for Variable Length Subnet Masking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SubnetHostsHostsBroadcast Address From To Address 172.16.0.0 172.16.0.1 172.16.255.254 172.16.255.255 172.16.0.0172.16.0.1 172.16.255.254 172.16.255.255 172.16.0.0 172.16.0.1 172.16.63.254172.16.63.255 172.16.64.0 172.16.64.1 172.16.127.254 172.16.127.255 172.16.128.0 172.16.128.1 172.16.191.254 172.16.191.255 172.16.192.0 172.16.192.1 172.16.255.254 172.16.255.255 Verified straight from the horses mouth (TAC IP Subnet Calculator) at CCO Cheers, Jack Norma Schutt [EMAIL PROTECTED] on 28/09/2000 09:10:32 AM Please respond to Norma Schutt [EMAIL PROTECTED] To: [EMAIL PROTECTED] cc:(bcc: Jack Jessen/Sydney/CDM) Subject: Fwd: Re: CCDA summerization question You can summarize on the first bit but you would need two summary address statements to cover all 4 networks: 172.16.0.0 mask 255.255.128.0 for the networks 172.16.0.0 and 172.16.64.0 172.16.128.0 mask 255.255.128.0 for the network 172.16.128.0 and 172.16.192.0 Regards, No Shut It would be the first 2 bits in the 3rd octet. Go back to subnetting these are network numbers with the netmask of 255.255.192.0 First 2 bits make 192. 256-192 = 64. 64, 128, 192 Scott P. "John lay" [EMAIL PROTECTED] wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... Guys, While studying for the CCDA, I found the following question in one of the exam preparation sites. The following IP addresses can be summaried by which bit of the 3rd octet 172.16.0.0, 172.16.64.0, 172.16.128.0, 172.16.192.0 --- 1st bit, first 2 bit, first 4 bit, last 6 bit I don't think that the following addresses could be summarized on any bit of the 3rd octet. If you have a look to the 3rd octet 172.16.0.0 --- 172.16..0 172.16.64.0 --- 172.16.0100.0 172.16.128.0--- 172.16.1000.0 172.16.192.0--- 172.16.1100.0 Could someone verify this with me guys ? Thanks a lot ___ Say Bye to Slow Internet! http://www.home.com/xinbox/signup.html **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] You can summarize on the first bit but you would need two summary address statements to cover all 4 networks: 172.16.0.0 mask 255.255.128.0 for the networks 172.16.0.0 and 172.16.64.0 172.16.128.0 mask 255.255.128.0 for the network 172.16.128.0 and 172.16.192.0 Regards, No Shut It would be the first 2 bits in the 3rd octet. Go back to subnetting these are network numbers with the netmask of 255.255.192.0 First 2 bits make 192. 256-192 = 64. 64, 128, 192 Scott P. John lay [EMAIL PROTECTED] wrote in message [EMAIL PROTECTED]" eudora="autourl">news:[EMAIL PROTECTED]... Guys, While studying for the CCDA, I found the following question in one of the exam preparation sites. The following IP addresses can be summaried by which bit of the 3rd octet 172.16.0.0, 172.16.64.0, 172.16.128.0, 172.16.192.0 --- 1st bit, first 2 bit, first 4 bit, last 6 bit I don't think that the following addresses could be summarized on any bit of the 3rd octet. If you have a look to the 3rd octet 172.16.0.0 --- 172.16..0 172.16.64.0 --- 172.16.0100.0 172.16.128.0--- 172.16.1000.0 172.16.192.0--- 172.16.1100.0 Could someone verify this with me guys ? Thanks a lot ___ Say Bye to Slow Internet! ht
Re: CCDA summerization question
i think it should be the first 2 bits.notice that "to be summaried".we know the summaried address is 172.16.0.0,it use the the first 3 bits to devide the subnet to 6 nets.due to the given situaton,the first 2 bits are summaried. i used to find the question in the CCDA true test and i passed it. tony yin MCSE,CCNA,CCDA "John lay" [EMAIL PROTECTED] wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... Guys, While studying for the CCDA, I found the following question in one of the exam preparation sites. The following IP addresses can be summaried by which bit of the 3rd octet 172.16.0.0, 172.16.64.0, 172.16.128.0, 172.16.192.0 --- 1st bit, first 2 bit, first 4 bit, last 6 bit I don't think that the following addresses could be summarized on any bit of the 3rd octet. If you have a look to the 3rd octet 172.16.0.0 --- 172.16..0 172.16.64.0 --- 172.16.0100.0 172.16.128.0--- 172.16.1000.0 172.16.192.0--- 172.16.1100.0 Could someone verify this with me guys ? Thanks a lot ___ Say Bye to Slow Internet! http://www.home.com/xinbox/signup.html **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
