Frequently asked questions

  Generally

  1. What is CIX?
    Croatian Internet eXchange (CIX) is a Croatian hub for exchanging internet traffic hosted at the University Computing Center (Srce), and open to all internet service providers in the Republic of Croatia, both for commercial and non-commercial, i.e. private networks.
  2. Who is connected to CIX?
    In addition to national and international internet service providers and non-commercial networks, CIX also welcomes internet service providers. You can find more details in the list of members.
  3. What are the costs of membership in CIX?
    For the first connection to CIX, a one-time fee of EUR 400.00 is paid. The monthly fee depends on the number and selected port bandwidth. For every second and each subsequent 10G connection, the discount is 50%. You can find more in the CIX service price list.
  4. If I order an additional connection to CIX, am I only required to pay the one-time fee for the first connection again?No, the one-time fee for the first connection is paid once after the contract is signed and the first connection is established on CIX.
  5. Does CIX support IPv6?
    Of course, IPv6 in CIX has a production status, that is, the contract applies to IPv6 traffic in the same way as it applies to IPv4.

Requirements

  1. What requirements do I have to fulfill in order to become a CIX member?
    The only requirement for connecting to CIX is a unique Autonomus System (AS) number and an active connection to the Internet. Members are expected to use their connection to CIX as a tool for optimizing national Internet traffic flows. The only allowed routing protocol on the CIX infrastructure is BGP4.
  2. Can I become a CIX member if I don't have an AS number?
    Unfortunately not. Within CIX (as well as other points for the exchange of Internet traffic), the AS number is a technical prerequisite for peering. CIX uses the Border Gateway Protocol (BGP) as a routing protocol, and it requires a unique Autonomous System Number (ASN).
  3. What is BGP?
    Border Gateway Protocol (BGP) is a standard routing protocol used by Internet service providers. The BGP protocol enables the exchange of routing information between autonomous systems; BGP is the technical basis for bilateral peering agreements between CIX members.
  4. Why do I have to configure BGP on my router if I want to connect to CIX?
    Without BGP, you are unable to exchange routing information with other CIX members.
  5. Is it possible to connect to CIX without hosting a router at one of the locations and a direct connection?
    Yes, it is possible. This option implies that a specific service provider of your choice provides a transparent layer 2 Ethernet connection to CIX. In this case, your company signs a contract with CIX and the Internet service provider, and thus you take responsibility for the quality of your remote connection. CIX reserves the right to disconnect an unstable remote connection in case of operational compromise of the traffic exchange point.
  6. Can I secure an Internet connection through CIX?
    CIX, as a neutral point for traffic exchange, provides a complementary network infrastructure. Commercial contracts between CIX members that involve the use of CIX's network infrastructure are not prohibited, but they are not supported by CIX either.
  7. Do I have a direct 10 Gbit connection to the Internet if I am connected to CIX with 10 Gbit bandwidth?
    You can connect to CIX with a bandwidth of 10 Gbit, but that does not mean that you can exchange 10 Gbit of traffic to the Internet. The amount of Internet traffic that actually passes through depends on the number and type of peering agreements you have with other CIX members.

Membership

  1. What do I need to do to become a CIX member?
    To become a CIX member, read the CIX regulations and the CIX contract and then contact us at cix@srce.hr. We will send you four copies of the prepared and signed CIX contract by regular mail. You must return two signed copies to us by regular mail.
  2. How do I physically connect to the CIX switch?
    For the purpose of connecting to the CIX switch at the CIX1 location, the CIX member provides the appropriate cable; the cable will be connected by Srce employees. Connecting to the CIX switch at the CIX2 location is performed according to the procedures of the Altus IT company.
  3. How can I access my equipment?
    The procedure for accessing the CIX member's equipment is described on the CIX internal website, https://intwww.cix.hr/public-content/support.

The process of joining CIX

  1. What is the procedure for connecting to CIX?
  • To prepare the contract template, we need the following information:
    • name of the legal entity
    • OIB
    • street and number
    • city and postal code
    • country
    • address for contract delivery
    • legal representative
    • e-mail address for official communication (alias)
    • AS number
  • We will send you the contract template for your comments and, if you agree with the text of the proposal, we will sign it.
  • We will send you the signed CIX contract in four copies by regular mail. You are required to return the two signed copies to us by regular mail.
  • After signing the contract, you will receive access to the IXP Manager application where you will enter your data and monitor traffic (bulk and peer to peer).
  • Next, the physical connection to CIX is implemented - you need to select the desired medium (https://www.cix.hr/en/services/ports) in order to ensure the appropriate SFP.
  • After the realization of the physical connection, you will receive IPv4 and IPv6 addresses and passwords for route servers.
  • We will announce on the CIX public website that you have connected to CIX, and we will inform the current members of CIX via e-mail, and you can start negotiations on the establishment of peering with those members who do not have open peering on the route servers.

 Access to equipment owned by CIX members

  1. Entering the CIX1(Srce, J. Marohnića 5).

Access to equipment owned by CIX members located in the CIX1 hub must be announced in advance via e-mail to cix@srce.hr. The e-mail should contain information about the person or persons coming, including names and time of arrival, as well as a brief description of the reason for arrival and the time required to perform the work.Note: persons must be nominated through the internal portal. 

  • Access to equipment and standard work during business hours (Mon-Fri, 8:00 AM - 4:00 PM) must be announced at least 24 hours in advance, otherwise it will be denied.
  • Access to equipment and standard work outside of business hours must be announced at least 48 hours in advance, otherwise it will be denied.
  • For urgent work, an email can be sent immediately before the intervention. In this case, it is important that the email subject begins with "URGENT INTERVENTION"; a brief description of the reason for the urgency must be provided.

  1. Input and output of equipment - CIX1.

    In case of equipment entry or withdrawal, prior notification is required via e-mail to cix@srce.hr. The e-mail must contain a list and serial numbers of the equipment.

    User equipment may be removed from the CIX1 node only with a report signed by an authorized technical person.

    In case of urgent work outside working hours, the equipment may be removed the next working day, with signed reports.

  2. Entering the CIX2 (Digital Realty, Selska cesta 93, Zagreb).
    Access to the equipment must be agreed with the Digital realty data center.

Technical details

  1. What technical details are important when connecting to a CIX switch?
    Important technical details can be found here.

Peering matrix

  1. What is a peering matrix and how is it obtained?
    The peering matrix shows data on which CIX members are open for mutual exchange of traffic through CIX. The peering matrix is ​​based on technical data automatically collected from the members.
  2. How to ''read'' the peering matrix?
    In the rows of the peering matrix for an individual member, we can read with which other members it wants to exchange traffic - there is a green square at the intersection of the row of the member with the column of the other member.
    Exchange of traffic takes place bilaterally, so both members want to exchange traffic, so in that case both members each have a green square in their row towards the other member.
    If only one member has a green square in its row towards another member, it means that it is ready to exchange, but the other member is not, and thus there is no exchange of traffic until the other member agrees.
  3. Peering matrix and open peering policy
    Open peering policy means that a member is willing to exchange traffic with all other members. In principle, such members are recognized as those with green boxes towards most other members, although this is not a sufficient condition to claim this with absolute certainty.
    With some probability you can see who the potential partners for traffic exchange are, but we advise that if certain members are important to you, you check directly with them whether they are interested in exchanging traffic with you.
  4. What can you learn from the peering matrix?
    With some probability you can see who the potential traffic exchange partners are, but we advise that if certain members are important to you, you check directly with them to see if they are interested in exchanging traffic with you.

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